diff --git a/DIRECTORY.md b/DIRECTORY.md index 4480f7892..a691a652b 100644 --- a/DIRECTORY.md +++ b/DIRECTORY.md @@ -46,6 +46,8 @@ * [Main Cll](https://github.com/TheAlgorithms/C-Plus-Plus/blob/master/data_structures/cll/main_cll.cpp) * [Disjoint Set](https://github.com/TheAlgorithms/C-Plus-Plus/blob/master/data_structures/disjoint_set.cpp) * [Doubly Linked List](https://github.com/TheAlgorithms/C-Plus-Plus/blob/master/data_structures/doubly_linked_list.cpp) + * [Dsu Path Compression](https://github.com/TheAlgorithms/C-Plus-Plus/blob/master/data_structures/dsu_path_compression.cpp) + * [Dsu Union Rank](https://github.com/TheAlgorithms/C-Plus-Plus/blob/master/data_structures/dsu_union_rank.cpp) * [Linked List](https://github.com/TheAlgorithms/C-Plus-Plus/blob/master/data_structures/linked_list.cpp) * [Linkedlist Implentation Usingarray](https://github.com/TheAlgorithms/C-Plus-Plus/blob/master/data_structures/linkedlist_implentation_usingarray.cpp) * [List Array](https://github.com/TheAlgorithms/C-Plus-Plus/blob/master/data_structures/list_array.cpp) @@ -163,6 +165,7 @@ * [Vector Ops](https://github.com/TheAlgorithms/C-Plus-Plus/blob/master/machine_learning/vector_ops.hpp) ## Math + * [Area](https://github.com/TheAlgorithms/C-Plus-Plus/blob/master/math/area.cpp) * [Armstrong Number](https://github.com/TheAlgorithms/C-Plus-Plus/blob/master/math/armstrong_number.cpp) * [Binary Exponent](https://github.com/TheAlgorithms/C-Plus-Plus/blob/master/math/binary_exponent.cpp) * [Binomial Calculate](https://github.com/TheAlgorithms/C-Plus-Plus/blob/master/math/binomial_calculate.cpp) @@ -241,7 +244,7 @@ * [Circular Queue Using Array](https://github.com/TheAlgorithms/C-Plus-Plus/blob/master/operations_on_datastructures/circular_queue_using_array.cpp) * [Get Size Of Linked List](https://github.com/TheAlgorithms/C-Plus-Plus/blob/master/operations_on_datastructures/get_size_of_linked_list.cpp) * [Inorder Successor Of Bst](https://github.com/TheAlgorithms/C-Plus-Plus/blob/master/operations_on_datastructures/inorder_successor_of_bst.cpp) - * [Intersection Of 2 Arrays](https://github.com/TheAlgorithms/C-Plus-Plus/blob/master/operations_on_datastructures/intersection_of_2_arrays.cpp) + * [Intersection Of Two Arrays](https://github.com/TheAlgorithms/C-Plus-Plus/blob/master/operations_on_datastructures/intersection_of_two_arrays.cpp) * [Reverse A Linked List Using Recusion](https://github.com/TheAlgorithms/C-Plus-Plus/blob/master/operations_on_datastructures/reverse_a_linked_list_using_recusion.cpp) * [Reverse Binary Tree](https://github.com/TheAlgorithms/C-Plus-Plus/blob/master/operations_on_datastructures/reverse_binary_tree.cpp) * [Selectionsortlinkedlist](https://github.com/TheAlgorithms/C-Plus-Plus/blob/master/operations_on_datastructures/selectionsortlinkedlist.cpp) diff --git a/data_structures/dsu_path_compression.cpp b/data_structures/dsu_path_compression.cpp new file mode 100644 index 000000000..a5c0aec33 --- /dev/null +++ b/data_structures/dsu_path_compression.cpp @@ -0,0 +1,213 @@ +/** + * @file + * @brief [DSU (Disjoint + * sets)](https://en.wikipedia.org/wiki/Disjoint-set-data_structure) + * @details + * It is a very powerful data structure that keeps track of different + * clusters(sets) of elements, these sets are disjoint(doesnot have a common + * element). Disjoint sets uses cases : for finding connected components in a + * graph, used in Kruskal's algorithm for finding Minimum Spanning tree. + * Operations that can be performed: + * 1) UnionSet(i,j): add(element i and j to the set) + * 2) findSet(i): returns the representative of the set to which i belogngs to. + * 3) get_max(i),get_min(i) : returns the maximum and minimum + * Below is the class-based approach which uses the heuristic of path + * compression. Using path compression in findSet(i),we are able to get to the + * representative of i in O(1) time. + * @author [AayushVyasKIIT](https://github.com/AayushVyasKIIT) + * @see dsu_union_rank.cpp + */ + +#include /// for assert +#include /// for IO operations +#include /// for std::vector + +using std::cout; +using std::endl; +using std::vector; + +/** + * @brief Disjoint sets union data structure, class based representation. + * @param n number of elements + */ +class dsu { + private: + vector p; ///< keeps track of the parent of ith element + vector depth; ///< tracks the depth(rank) of i in the tree + vector setSize; ///< size of each chunk(set) + vector maxElement; ///< maximum of each set to which i belongs to + vector minElement; ///< minimum of each set to which i belongs to + public: + /** + * @brief contructor for initialising all data members. + * @param n number of elements + */ + explicit dsu(uint64_t n) { + p.assign(n, 0); + /// initially, all of them are their own parents + for (uint64_t i = 0; i < n; i++) { + p[i] = i; + } + /// initially all have depth are equals to zero + depth.assign(n, 0); + maxElement.assign(n, 0); + minElement.assign(n, 0); + for (uint64_t i = 0; i < n; i++) { + depth[i] = 0; + maxElement[i] = i; + minElement[i] = i; + } + setSize.assign(n, 0); + /// initially set size will be equals to one + for (uint64_t i = 0; i < n; i++) { + setSize[i] = 1; + } + } + + /** + * @brief Method to find the representative of the set to which i belongs + * to, T(n) = O(1) + * @param i element of some set + * @returns representative of the set to which i belongs to. + */ + uint64_t findSet(uint64_t i) { + /// using path compression + if (p[i] == i) { + return i; + } + return (p[i] = findSet(p[i])); + } + /** + * @brief Method that combines two disjoint sets to which i and j belongs to + * and make a single set having a common representative. + * @param i element of some set + * @param j element of some set + * @returns void + */ + void UnionSet(uint64_t i, uint64_t j) { + /// check if both belongs to the same set or not + if (isSame(i, j)) { + return; + } + + // we find the representative of the i and j + uint64_t x = findSet(i); + uint64_t y = findSet(j); + + /// always keeping the min as x + /// shallow tree + if (depth[x] > depth[y]) { + std::swap(x, y); + } + /// making the shallower root's parent the deeper root + p[x] = y; + + /// if same depth, then increase one's depth + if (depth[x] == depth[y]) { + depth[y]++; + } + /// total size of the resultant set + setSize[y] += setSize[x]; + /// changing the maximum elements + maxElement[y] = std::max(maxElement[x], maxElement[y]); + minElement[y] = std::min(minElement[x], minElement[y]); + } + /** + * @brief A utility function which check whether i and j belongs to + * same set or not + * @param i element of some set + * @param j element of some set + * @returns `true` if element `i` and `j` ARE in the same set + * @returns `false` if element `i` and `j` are NOT in same set + */ + bool isSame(uint64_t i, uint64_t j) { + if (findSet(i) == findSet(j)) { + return true; + } + return false; + } + /** + * @brief prints the minimum, maximum and size of the set to which i belongs + * to + * @param i element of some set + * @returns void + */ + vector get(uint64_t i) { + vector ans; + ans.push_back(get_min(i)); + ans.push_back(get_max(i)); + ans.push_back(size(i)); + return ans; + } + /** + * @brief A utility function that returns the size of the set to which i + * belongs to + * @param i element of some set + * @returns size of the set to which i belongs to + */ + uint64_t size(uint64_t i) { return setSize[findSet(i)]; } + /** + * @brief A utility function that returns the max element of the set to + * which i belongs to + * @param i element of some set + * @returns maximum of the set to which i belongs to + */ + uint64_t get_max(uint64_t i) { return maxElement[findSet(i)]; } + /** + * @brief A utility function that returns the min element of the set to + * which i belongs to + * @param i element of some set + * @returns minimum of the set to which i belongs to + */ + uint64_t get_min(uint64_t i) { return minElement[findSet(i)]; } +}; + +/** + * @brief Self-test implementations, 1st test + * @returns void + */ +static void test1() { + // the minimum, maximum, and size of the set + uint64_t n = 10; ///< number of items + dsu d(n + 1); ///< object of class disjoint sets + // set 1 + d.UnionSet(1, 2); // performs union operation on 1 and 2 + d.UnionSet(1, 4); // performs union operation on 1 and 4 + vector ans = {1, 4, 3}; + for (uint64_t i = 0; i < ans.size(); i++) { + assert(d.get(4).at(i) == ans[i]); // makes sure algorithm works fine + } + cout << "1st test passed!" << endl; +} +/** + * @brief Self-implementations, 2nd test + * @returns void + */ +static void test2() { + // the minimum, maximum, and size of the set + uint64_t n = 10; ///< number of items + dsu d(n + 1); ///< object of class disjoint sets + // set 1 + d.UnionSet(3, 5); + d.UnionSet(5, 6); + d.UnionSet(5, 7); + vector ans = {3, 7, 4}; + for (uint64_t i = 0; i < ans.size(); i++) { + assert(d.get(3).at(i) == ans[i]); // makes sure algorithm works fine + } + cout << "2nd test passed!" << endl; +} + +/** + * @brief Main function + * @returns 0 on exit + * */ +int main() { + uint64_t n = 10; ///< number of items + dsu d(n + 1); ///< object of class disjoint sets + + test1(); // run 1st test case + test2(); // run 2nd test case + + return 0; +} diff --git a/data_structures/dsu_union_rank.cpp b/data_structures/dsu_union_rank.cpp new file mode 100644 index 000000000..8936d6d69 --- /dev/null +++ b/data_structures/dsu_union_rank.cpp @@ -0,0 +1,187 @@ +/** + * @file + * @brief [DSU (Disjoint + * sets)](https://en.wikipedia.org/wiki/Disjoint-set-data_structure) + * @details + * dsu : It is a very powerful data structure which keeps track of different + * clusters(sets) of elements, these sets are disjoint(doesnot have a common + * element). Disjoint sets uses cases : for finding connected components in a + * graph, used in Kruskal's algorithm for finding Minimum Spanning tree. + * Operations that can be performed: + * 1) UnionSet(i,j): add(element i and j to the set) + * 2) findSet(i): returns the representative of the set to which i belogngs to. + * 3) getParents(i): prints the parent of i and so on and so forth. + * Below is the class-based approach which uses the heuristic of union-ranks. + * Using union-rank in findSet(i),we are able to get to the representative of i + * in slightly delayed O(logN) time but it allows us to keep tracks of the + * parent of i. + * @author [AayushVyasKIIT](https://github.com/AayushVyasKIIT) + * @see dsu_path_compression.cpp + */ + +#include /// for assert +#include /// for IO operations +#include /// for std::vector + +using std::cout; +using std::endl; +using std::vector; + +/** + * @brief Disjoint sets union data structure, class based representation. + * @param n number of elements + */ +class dsu { + private: + vector p; ///< keeps track of the parent of ith element + vector depth; ///< tracks the depth(rank) of i in the tree + vector setSize; ///< size of each chunk(set) + public: + /** + * @brief constructor for initialising all data members + * @param n number of elements + */ + explicit dsu(uint64_t n) { + p.assign(n, 0); + /// initially all of them are their own parents + depth.assign(n, 0); + setSize.assign(n, 0); + for (uint64_t i = 0; i < n; i++) { + p[i] = i; + depth[i] = 0; + setSize[i] = 1; + } + } + /** + * @brief Method to find the representative of the set to which i belongs + * to, T(n) = O(logN) + * @param i element of some set + * @returns representative of the set to which i belongs to + */ + uint64_t findSet(uint64_t i) { + /// using union-rank + while (i != p[i]) { + i = p[i]; + } + return i; + } + /** + * @brief Method that combines two disjoint sets to which i and j belongs to + * and make a single set having a common representative. + * @param i element of some set + * @param j element of some set + * @returns void + */ + void unionSet(uint64_t i, uint64_t j) { + /// checks if both belongs to same set or not + if (isSame(i, j)) { + return; + } + /// we find representative of the i and j + uint64_t x = findSet(i); + uint64_t y = findSet(j); + + /// always keeping the min as x + /// in order to create a shallow tree + if (depth[x] > depth[y]) { + std::swap(x, y); + } + /// making the shallower tree, root parent of the deeper root + p[x] = y; + + /// if same depth, then increase one's depth + if (depth[x] == depth[y]) { + depth[y]++; + } + /// total size of the resultant set + setSize[y] += setSize[x]; + } + /** + * @brief A utility function which check whether i and j belongs to same set + * or not + * @param i element of some set + * @param j element of some set + * @returns `true` if element i and j are in same set + * @returns `false` if element i and j are not in same set + */ + bool isSame(uint64_t i, uint64_t j) { + if (findSet(i) == findSet(j)) { + return true; + } + return false; + } + /** + * @brief Method to print all the parents of i, or the path from i to + * representative. + * @param i element of some set + * @returns void + */ + vector getParents(uint64_t i) { + vector ans; + while (p[i] != i) { + ans.push_back(i); + i = p[i]; + } + ans.push_back(i); + return ans; + } +}; +/** + * @brief Self-implementations, 1st test + * @returns void + */ +static void test1() { + /* checks the parents in the resultant structures */ + uint64_t n = 10; ///< number of elements + dsu d(n + 1); ///< object of class disjoint sets + d.unionSet(2, 1); ///< performs union operation on 1 and 2 + d.unionSet(1, 4); + d.unionSet(8, 1); + d.unionSet(3, 5); + d.unionSet(5, 6); + d.unionSet(5, 7); + d.unionSet(9, 10); + d.unionSet(2, 10); + // keeping track of the changes using parent pointers + vector ans = {7, 5}; + for (uint64_t i = 0; i < ans.size(); i++) { + assert(d.getParents(7).at(i) == + ans[i]); // makes sure algorithm works fine + } + cout << "1st test passed!" << endl; +} +/** + * @brief Self-implementations, 2nd test + * @returns void + */ +static void test2() { + // checks the parents in the resultant structures + uint64_t n = 10; ///< number of elements + dsu d(n + 1); ///< object of class disjoint sets + d.unionSet(2, 1); /// performs union operation on 1 and 2 + d.unionSet(1, 4); + d.unionSet(8, 1); + d.unionSet(3, 5); + d.unionSet(5, 6); + d.unionSet(5, 7); + d.unionSet(9, 10); + d.unionSet(2, 10); + + /// keeping track of the changes using parent pointers + vector ans = {2, 1, 10}; + for (uint64_t i = 0; i < ans.size(); i++) { + assert(d.getParents(2).at(i) == + ans[i]); /// makes sure algorithm works fine + } + cout << "2nd test passed!" << endl; +} +/** + * @brief Main function + * @returns 0 on exit + */ +int main() { + test1(); // run 1st test case + test2(); // run 2nd test case + + return 0; +} diff --git a/math/area.cpp b/math/area.cpp new file mode 100644 index 000000000..6983cf3e4 --- /dev/null +++ b/math/area.cpp @@ -0,0 +1,274 @@ +/** + * @file + * @brief Implementations for the [area](https://en.wikipedia.org/wiki/Area) of various shapes + * @details The area of a shape is the amount of 2D space it takes up. + * All shapes have a formula to get the area of any given shape. + * These implementations support multiple return types. + * + * @author [Focusucof](https://github.com/Focusucof) + */ +#define _USE_MATH_DEFINES +#include /// for M_PI definition and pow() +#include /// for uint16_t datatype +#include /// for IO operations +#include /// for assert + +/** + * @namespace math + * @brief Mathematical algorithms + */ +namespace math { +/** + * @brief area of a [square](https://en.wikipedia.org/wiki/Square) (l * l) + * @param length is the length of the square + * @returns area of square + */ +template +T square_area(T length) { + return length * length; +} + +/** + * @brief area of a [rectangle](https://en.wikipedia.org/wiki/Rectangle) (l * w) + * @param length is the length of the rectangle + * @param width is the width of the rectangle + * @returns area of the rectangle + */ +template +T rect_area(T length, T width) { + return length * width; +} + +/** + * @brief area of a [triangle](https://en.wikipedia.org/wiki/Triangle) (b * h / + * 2) + * @param base is the length of the bottom side of the triangle + * @param height is the length of the tallest point in the triangle + * @returns area of the triangle + */ +template +T triangle_area(T base, T height) { + return base * height / 2; +} + +/** + * @brief area of a [circle](https://en.wikipedia.org/wiki/Area_of_a_circle) (pi + * * r^2) + * @param radius is the radius of the circle + * @returns area of the circle + */ +template +T circle_area(T radius) { + return M_PI * pow(radius, 2); +} + +/** + * @brief area of a [parallelogram](https://en.wikipedia.org/wiki/Parallelogram) + * (b * h) + * @param base is the length of the bottom side of the parallelogram + * @param height is the length of the tallest point in the parallelogram + * @returns area of the parallelogram + */ +template +T parallelogram_area(T base, T height) { + return base * height; +} + +/** + * @brief surface area of a [cube](https://en.wikipedia.org/wiki/Cube) ( 6 * (l + * * l)) + * @param length is the length of the cube + * @returns surface area of the cube + */ +template +T cube_surface_area(T length) { + return 6 * length * length; +} + +/** + * @brief surface area of a [sphere](https://en.wikipedia.org/wiki/Sphere) ( 4 * + * pi * r^2) + * @param radius is the radius of the sphere + * @returns surface area of the sphere + */ +template +T sphere_surface_area(T radius) { + return 4 * M_PI * pow(radius, 2); +} + +/** + * @brief surface area of a [cylinder](https://en.wikipedia.org/wiki/Cylinder) + * (2 * pi * r * h + 2 * pi * r^2) + * @param radius is the radius of the cylinder + * @param height is the height of the cylinder + * @returns surface area of the cylinder + */ +template +T cylinder_surface_area(T radius, T height) { + return 2 * M_PI * radius * height + 2 * M_PI * pow(radius, 2); +} +} // namespace math + +/** + * @brief Self-test implementations + * @returns void + */ +static void test() { + // I/O variables for testing + uint16_t int_length; // 16 bit integer length input + uint16_t int_width; // 16 bit integer width input + uint16_t int_base; // 16 bit integer base input + uint16_t int_height; // 16 bit integer height input + uint16_t int_expected; // 16 bit integer expected output + uint16_t int_area; // 16 bit integer output + + float float_length; // float length input + float float_expected; // float expected output + float float_area; // float output + + double double_length; // double length input + double double_width; // double width input + double double_radius; // double radius input + double double_height; // double height input + double double_expected; // double expected output + double double_area; // double output + + // 1st test + int_length = 5; + int_expected = 25; + int_area = math::square_area(int_length); + + std::cout << "AREA OF A SQUARE (int)" << std::endl; + std::cout << "Input Length: " << int_length << std::endl; + std::cout << "Expected Output: " << int_expected << std::endl; + std::cout << "Output: " << int_area << std::endl; + assert(int_area == int_expected); + std::cout << "TEST PASSED" << std::endl << std::endl; + + // 2nd test + float_length = 2.5; + float_expected = 6.25; + float_area = math::square_area(float_length); + + std::cout << "AREA OF A SQUARE (float)" << std::endl; + std::cout << "Input Length: " << float_length << std::endl; + std::cout << "Expected Output: " << float_expected << std::endl; + std::cout << "Output: " << float_area << std::endl; + assert(float_area == float_expected); + std::cout << "TEST PASSED" << std::endl << std::endl; + + // 3rd test + int_length = 4; + int_width = 7; + int_expected = 28; + int_area = math::rect_area(int_length, int_width); + + std::cout << "AREA OF A RECTANGLE (int)" << std::endl; + std::cout << "Input Length: " << int_length << std::endl; + std::cout << "Input Width: " << int_width << std::endl; + std::cout << "Expected Output: " << int_expected << std::endl; + std::cout << "Output: " << int_area << std::endl; + assert(int_area == int_expected); + std::cout << "TEST PASSED" << std::endl << std::endl; + + // 4th test + double_length = 2.5; + double_width = 5.7; + double_expected = 14.25; + double_area = math::rect_area(double_length, double_width); + + std::cout << "AREA OF A RECTANGLE (double)" << std::endl; + std::cout << "Input Length: " << double_length << std::endl; + std::cout << "Input Width: " << double_width << std::endl; + std::cout << "Expected Output: " << double_expected << std::endl; + std::cout << "Output: " << double_area << std::endl; + assert(double_area == double_expected); + std::cout << "TEST PASSED" << std::endl << std::endl; + + // 5th test + int_base = 10; + int_height = 3; + int_expected = 15; + int_area = math::triangle_area(int_base, int_height); + + std::cout << "AREA OF A TRIANGLE" << std::endl; + std::cout << "Input Base: " << int_base << std::endl; + std::cout << "Input Height: " << int_height << std::endl; + std::cout << "Expected Output: " << int_expected << std::endl; + std::cout << "Output: " << int_area << std::endl; + assert(int_area == int_expected); + std::cout << "TEST PASSED" << std::endl << std::endl; + + // 6th test + double_radius = 6; + double_expected = 113.09733552923255; // rounded down because the double datatype truncates after 14 decimal places + double_area = math::circle_area(double_radius); + + std::cout << "AREA OF A CIRCLE" << std::endl; + std::cout << "Input Radius: " << double_radius << std::endl; + std::cout << "Expected Output: " << double_expected << std::endl; + std::cout << "Output: " << double_area << std::endl; + assert(double_area == double_expected); + std::cout << "TEST PASSED" << std::endl << std::endl; + + // 7th test + int_base = 6; + int_height = 7; + int_expected = 42; + int_area = math::parallelogram_area(int_base, int_height); + + std::cout << "AREA OF A PARALLELOGRAM" << std::endl; + std::cout << "Input Base: " << int_base << std::endl; + std::cout << "Input Height: " << int_height << std::endl; + std::cout << "Expected Output: " << int_expected << std::endl; + std::cout << "Output: " << int_area << std::endl; + assert(int_area == int_expected); + std::cout << "TEST PASSED" << std::endl << std::endl; + + // 8th test + double_length = 5.5; + double_expected = 181.5; + double_area = math::cube_surface_area(double_length); + + std::cout << "SURFACE AREA OF A CUBE" << std::endl; + std::cout << "Input Length: " << double_length << std::endl; + std::cout << "Expected Output: " << double_expected << std::endl; + std::cout << "Output: " << double_area << std::endl; + assert(double_area == double_expected); + std::cout << "TEST PASSED" << std::endl << std::endl; + + // 9th test + double_radius = 10.0; + double_expected = 1256.6370614359172; // rounded down because the whole value gets truncated + double_area = math::sphere_surface_area(double_radius); + + std::cout << "SURFACE AREA OF A SPHERE" << std::endl; + std::cout << "Input Radius: " << double_radius << std::endl; + std::cout << "Expected Output: " << double_expected << std::endl; + std::cout << "Output: " << double_area << std::endl; + assert(double_area == double_expected); + std::cout << "TEST PASSED" << std::endl << std::endl; + + // 10th test + double_radius = 4.0; + double_height = 7.0; + double_expected = 276.46015351590177; + double_area = math::cylinder_surface_area(double_radius, double_height); + + std::cout << "SURFACE AREA OF A CYLINDER" << std::endl; + std::cout << "Input Radius: " << double_radius << std::endl; + std::cout << "Input Height: " << double_height << std::endl; + std::cout << "Expected Output: " << double_expected << std::endl; + std::cout << "Output: " << double_area << std::endl; + assert(double_area == double_expected); + std::cout << "TEST PASSED" << std::endl << std::endl; +} + +/** + * @brief Main function + * @returns 0 on exit + */ +int main() { + test(); // run self-test implementations + return 0; +} diff --git a/operations_on_datastructures/array_right_rotation.cpp b/operations_on_datastructures/array_right_rotation.cpp index 8b01a2003..65e8536f4 100644 --- a/operations_on_datastructures/array_right_rotation.cpp +++ b/operations_on_datastructures/array_right_rotation.cpp @@ -1,27 +1,175 @@ -#include -using namespace std; -int main() { - int n, k; - cout << "Enter size of array=\t"; - cin >> n; - cout << "Enter Number of indices u want to rotate the array to right=\t"; - cin >> k; - int a[n]; - cout << "Enter elements of array=\t"; - for (int i = 0; i < n; i++) cin >> a[i]; - int temp = 0; - for (int i = 0; i < k; i++) { - temp = a[n - 1]; - for (int j = n - 1; j >= 0; j--) { - if (j == 0) { - a[j] = temp; - } else { - a[j] = a[j - 1]; - } - } - } - cout << "Your rotated array is=\t"; - for (int i = 0; i < n; i++) { - cout << a[i] << " "; +/** + * @file + * @brief Implementation for the [Array right + * Rotation](https://www.javatpoint.com/program-to-right-rotate-the-elements-of-an-array) + * algorithm. + * @details Shifting an array to the right involves moving each element of the + * array so that it occupies a position of a certain shift value after its + * current one. This implementation uses a result vector and does not mutate the + * input. + * @see array_left_rotation.cpp + * @author [Alvin](https://github.com/polarvoid) + */ + +#include /// for assert +#include /// for IO operations +#include /// for std::vector + +/** + * @namespace operations_on_datastructures + * @brief Operations on Data Structures + */ +namespace operations_on_datastructures { + +/** + * @brief Prints the values of a vector sequentially, ending with a newline + * character. + * @param array Reference to the array to be printed + * @returns void + */ +void print(const std::vector &array) { + for (int32_t i : array) { + std::cout << i << " "; /// Print each value in the array } + std::cout << "\n"; /// Print newline +} + +/** + * @brief Shifts the given vector to the right by the shift amount and returns a + * new vector with the result. The original vector is not mutated. + * @details Shifts the values of the vector, by creating a new vector and adding + * values from the shift index to the end, then appending the rest of the + * elements to the start of the vector. + * @param array A reference to the input std::vector + * @param shift The amount to be shifted to the right + * @returns A std::vector with the shifted values + */ +std::vector shift_right(const std::vector &array, + size_t shift) { + if (array.size() <= shift) { + return {}; ///< We got an invalid shift, return empty array + } + std::vector res(array.size()); ///< Result array + for (size_t i = shift; i < array.size(); i++) { + res[i] = array[i - shift]; ///< Add values after the shift index + } + for (size_t i = 0; i < shift; i++) { + res[i] = + array[array.size() - shift + i]; ///< Add the values from the start + } + return res; +} + +} // namespace operations_on_datastructures + +/** + * @namespace tests + * @brief Testcases to check Union of Two Arrays. + */ +namespace tests { +using operations_on_datastructures::print; +using operations_on_datastructures::shift_right; +/** + * @brief A Test to check an simple case + * @returns void + */ +void test1() { + std::cout << "TEST CASE 1\n"; + std::cout << "Initialized arr = {1, 2, 3, 4, 5}\n"; + std::cout << "Expected result: {4, 5, 1, 2, 3}\n"; + std::vector arr = {1, 2, 3, 4, 5}; + std::vector res = shift_right(arr, 2); + std::vector expected = {4, 5, 1, 2, 3}; + assert(res == expected); + print(res); ///< Should print 4 5 1 2 3 + std::cout << "TEST PASSED!\n\n"; +} +/** + * @brief A Test to check an empty vector + * @returns void + */ +void test2() { + std::cout << "TEST CASE 2\n"; + std::cout << "Initialized arr = {}\n"; + std::cout << "Expected result: {}\n"; + std::vector arr = {}; + std::vector res = shift_right(arr, 2); + std::vector expected = {}; + assert(res == expected); + print(res); ///< Should print empty newline + std::cout << "TEST PASSED!\n\n"; +} +/** + * @brief A Test to check an invalid shift value + * @returns void + */ +void test3() { + std::cout << "TEST CASE 3\n"; + std::cout << "Initialized arr = {1, 2, 3, 4, 5}\n"; + std::cout << "Expected result: {}\n"; + std::vector arr = {1, 2, 3, 4, 5}; + std::vector res = shift_right(arr, 7); ///< 7 > 5 + std::vector expected = {}; + assert(res == expected); + print(res); ///< Should print empty newline + std::cout << "TEST PASSED!\n\n"; +} +/** + * @brief A Test to check a very large input + * @returns void + */ +void test4() { + std::cout << "TEST CASE 4\n"; + std::cout << "Initialized arr = {2, 4, ..., 420}\n"; + std::cout << "Expected result: {420, 2, 4, ..., 418}\n"; + std::vector arr; + for (int i = 1; i <= 210; i++) { + arr.push_back(i * 2); + } + print(arr); + std::vector res = shift_right(arr, 1); + std::vector expected; + expected.push_back(420); + for (int i = 0; i < 209; i++) { + expected.push_back(arr[i]); + } + assert(res == expected); + print(res); ///< Should print {420, 2, 4, ..., 418} + std::cout << "TEST PASSED!\n\n"; +} +/** + * @brief A Test to check a shift of zero + * @returns void + */ +void test5() { + std::cout << "TEST CASE 5\n"; + std::cout << "Initialized arr = {1, 2, 3, 4, 5}\n"; + std::cout << "Expected result: {1, 2, 3, 4, 5}\n"; + std::vector arr = {1, 2, 3, 4, 5}; + std::vector res = shift_right(arr, 0); + assert(res == arr); + print(res); ///< Should print 1 2 3 4 5 + std::cout << "TEST PASSED!\n\n"; +} +} // namespace tests + +/** + * @brief Function to test the correctness of shift_right() function + * @returns void + */ +static void test() { + tests::test1(); + tests::test2(); + tests::test3(); + tests::test4(); + tests::test5(); +} + +/** + * @brief main function + * @returns 0 on exit + */ +int main() { + test(); // run self-test implementations + return 0; } diff --git a/operations_on_datastructures/intersection_of_2_arrays.cpp b/operations_on_datastructures/intersection_of_2_arrays.cpp deleted file mode 100644 index 8a3b27edf..000000000 --- a/operations_on_datastructures/intersection_of_2_arrays.cpp +++ /dev/null @@ -1,26 +0,0 @@ -#include -int main() { - int i, j, m, n; - cout << "Enter size of array 1:"; - cin >> m; - cout << "Enter size of array 2:"; - cin >> n; - int a[m]; - int b[n]; - cout << "Enter elements of array 1:"; - for (i = 0; i < m; i++) cin >> a[i]; - for (i = 0; i < n; i++) cin >> b[i]; - i = 0; - j = 0; - while ((i < m) && (j < n)) { - if (a[i] < b[j]) - i++; - else if (a[i] > b[j]) - j++; - else { - cout << a[i++] << " "; - j++; - } - } - return 0; -} diff --git a/operations_on_datastructures/intersection_of_two_arrays.cpp b/operations_on_datastructures/intersection_of_two_arrays.cpp new file mode 100644 index 000000000..c660f505b --- /dev/null +++ b/operations_on_datastructures/intersection_of_two_arrays.cpp @@ -0,0 +1,203 @@ +/** + * @file + * @brief Implementation for the [Intersection of two sorted + * Arrays](https://en.wikipedia.org/wiki/Intersection_(set_theory)) + * algorithm. + * @details The intersection of two arrays is the collection of all the elements + * that are common in both the first and second arrays. This implementation uses + * ordered arrays, and an algorithm to correctly order them and return the + * result as a new array (vector). + * @see union_of_two_arrays.cpp + * @author [Alvin](https://github.com/polarvoid) + */ + +#include /// for std::sort +#include /// for assert +#include /// for IO operations +#include /// for std::vector + +/** + * @namespace operations_on_datastructures + * @brief Operations on Data Structures + */ +namespace operations_on_datastructures { + +/** + * @brief Prints the values of a vector sequentially, ending with a newline + * character. + * @param array Reference to the array to be printed + * @returns void + */ +void print(const std::vector &array) { + for (int32_t i : array) { + std::cout << i << " "; /// Print each value in the array + } + std::cout << "\n"; /// Print newline +} + +/** + * @brief Gets the intersection of two sorted arrays, and returns them in a + * vector. + * @details An algorithm is used that compares the elements of the two vectors, + * incrementing the index of the smaller of the two. If the elements are the + * same, the element is appended to the result array to be returned. + * @param first A std::vector of sorted integer values + * @param second A std::vector of sorted integer values + * @returns A std::vector of the intersection of the two arrays, in ascending + * order + */ +std::vector get_intersection(const std::vector &first, + const std::vector &second) { + std::vector res; ///< Vector to hold the intersection + size_t f_index = 0; ///< Index for the first array + size_t s_index = 0; ///< Index for the second array + size_t f_length = first.size(); ///< Length of first array + size_t s_length = second.size(); ///< Length of second array + + while (f_index < f_length && s_index < s_length) { + if (first[f_index] < second[s_index]) { + f_index++; ///< Increment index of second array + } else if (first[f_index] > second[s_index]) { + s_index++; ///< Increment index of second array + } else { + if ((res.size() == 0) || (first[f_index] != res.back())) { + res.push_back( + first[f_index]); ///< Add the element if it is unique + } + f_index++; ///< Increment index of first array + s_index++; ///< Increment index of second array too + } + } + return res; +} + +} // namespace operations_on_datastructures + +/** + * @namespace tests + * @brief Testcases to check intersection of Two Arrays. + */ +namespace tests { +using operations_on_datastructures::get_intersection; +using operations_on_datastructures::print; +/** + * @brief A Test to check an edge case (two empty arrays) + * @returns void + */ +void test1() { + std::cout << "TEST CASE 1\n"; + std::cout << "Intialized a = {} b = {}\n"; + std::cout << "Expected result: {}\n"; + std::vector a = {}; + std::vector b = {}; + std::vector result = get_intersection(a, b); + assert(result == a); ///< Check if result is empty + print(result); ///< Should only print newline + std::cout << "TEST PASSED!\n\n"; +} +/** + * @brief A Test to check an edge case (one empty array) + * @returns void + */ +void test2() { + std::cout << "TEST CASE 2\n"; + std::cout << "Intialized a = {} b = {2, 3}\n"; + std::cout << "Expected result: {}\n"; + std::vector a = {}; + std::vector b = {2, 3}; + std::vector result = get_intersection(a, b); + assert(result == a); ///< Check if result is equal to a + print(result); ///< Should only print newline + std::cout << "TEST PASSED!\n\n"; +} +/** + * @brief A Test to check correct functionality with a simple test case + * @returns void + */ +void test3() { + std::cout << "TEST CASE 3\n"; + std::cout << "Intialized a = {4, 6} b = {3, 6}\n"; + std::cout << "Expected result: {6}\n"; + std::vector a = {4, 6}; + std::vector b = {3, 6}; + std::vector result = get_intersection(a, b); + std::vector expected = {6}; + assert(result == expected); ///< Check if result is correct + print(result); ///< Should print 6 + std::cout << "TEST PASSED!\n\n"; +} +/** + * @brief A Test to check correct functionality with duplicate values + * @returns void + */ +void test4() { + std::cout << "TEST CASE 4\n"; + std::cout << "Intialized a = {4, 6, 6, 6} b = {2, 4, 4, 6}\n"; + std::cout << "Expected result: {4, 6}\n"; + std::vector a = {4, 6, 6, 6}; + std::vector b = {2, 4, 4, 6}; + std::vector result = get_intersection(a, b); + std::vector expected = {4, 6}; + assert(result == expected); ///< Check if result is correct + print(result); ///< Should print 4 6 + std::cout << "TEST PASSED!\n\n"; +} +/** + * @brief A Test to check correct functionality with a harder test case + * @returns void + */ +void test5() { + std::cout << "TEST CASE 5\n"; + std::cout << "Intialized a = {1, 2, 3, 4, 6, 7, 9} b = {2, 3, 4, 5}\n"; + std::cout << "Expected result: {2, 3, 4}\n"; + std::vector a = {1, 2, 3, 4, 6, 7, 9}; + std::vector b = {2, 3, 4, 5}; + std::vector result = get_intersection(a, b); + std::vector expected = {2, 3, 4}; + assert(result == expected); ///< Check if result is correct + print(result); ///< Should print 2 3 4 + std::cout << "TEST PASSED!\n\n"; +} +/** + * @brief A Test to check correct functionality with an array sorted using + * std::sort + * @returns void + */ +void test6() { + std::cout << "TEST CASE 6\n"; + std::cout << "Intialized a = {1, 3, 3, 2, 5, 9, 4, 7, 3, 2} "; + std::cout << "b = {11, 3, 7, 8, 6}\n"; + std::cout << "Expected result: {3, 7}\n"; + std::vector a = {1, 3, 3, 2, 5, 9, 4, 7, 3, 2}; + std::vector b = {11, 3, 7, 8, 6}; + std::sort(a.begin(), a.end()); ///< Sort vector a + std::sort(b.begin(), b.end()); ///< Sort vector b + std::vector result = get_intersection(a, b); + std::vector expected = {3, 7}; + assert(result == expected); ///< Check if result is correct + print(result); ///< Should print 3 7 + std::cout << "TEST PASSED!\n\n"; +} +} // namespace tests + +/** + * @brief Function to test the correctness of get_intersection() function + * @returns void + */ +static void test() { + tests::test1(); + tests::test2(); + tests::test3(); + tests::test4(); + tests::test5(); + tests::test6(); +} + +/** + * @brief main function + * @returns 0 on exit + */ +int main() { + test(); // run self-test implementations + return 0; +}