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file renamed to kadanes3.cpp and clang-tidy warnings fixed

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Abhijeet Tiwari
2021-10-05 10:04:26 +05:30
parent 8f2b67906a
commit b7f81a5d2e
2 changed files with 91 additions and 83 deletions
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83
others/kadanes.cpp
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@@ -1,83 +0,0 @@
/**
* @file
* @brief Efficient implemention for maximum contiguos subarray sum by kadane's algorithm.
* @details
* Our task is to take length of array and then the whole array as input from
* the user and then calculate the maximum contiguos subarray sum for the
* input array, using the kadane's algorithm.
*
* reference article : https://www.geeksforgeeks.org/largest-sum-contiguous-subarray/
*
* There can be a case that all the elements in the input array are negative.
* In that case, the least value among all elements is the maximum sum with subarray
* length = 1.
* @author [Abhijeet Tiwari](https://github.com/thisabhijeet)
*/
#include <cassert> // for assert
#include <iostream> // for io operations
#include <climits> // for INT_MIN value
using namespace std;
/** max_subarray_sum function
* \param arr input array
* \param length length of the input array
* \returns maximum contiguous subarray sum
*/
int max_subarray_sum(int arr[], int length)
{
int current_max = INT_MIN, current_sum = 0;
for (int i = 0; i < length; i++)
{
current_sum = current_sum + arr[i];
if (current_max < current_sum)
{
current_max = current_sum;
}
if (current_sum < 0)
{
current_sum = 0;
}
}
return current_max;
}
/**
* @brief Self-test implementations
* @returns void
*/
static void test()
{
int arr[4] = {1, 2, 3, 4};
int arr1[5] = {-1, -2, -4, -6, 7};
assert(max_subarray_sum(arr, 4) == 10);
assert(max_subarray_sum(arr1, 5) == 7);
cout << "all test cases passed!";
}
/** main function */
int main()
{ // Below is the code for accepting array from user and then calling
// the function for the required output.
// It has been commented for now so that the test() function can run
// and test cases can be verified.
// code for accepting array from user starts
// int n; // variable for length of input array
// cout << "Enter length of the array: ";
// cin >> n;
// int arr[n];
// for (int i = 0; i < n; i++) // taking input of each element of the array
// {
// cin >> arr[i];
// }
// int max_sum = max_subarray_sum(arr, n);
// cout << "Maximum contiguous sum for this array is : " << max_sum << endl;
// code for accepting array from user ends
test();
return 0;
}

91
others/kadanes3.cpp Normal file
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/**
* @file
* @brief Efficient implemention for maximum contiguos subarray sum by kadane's
* algorithm.
* @details
* Our task is to take length of array and then the whole array as input from
* the user and then calculate the maximum contiguos subarray sum for the
* input array, using the kadane's algorithm.
*
* reference article :
* https://www.geeksforgeeks.org/largest-sum-contiguous-subarray/
*
* There can be a case that all the elements in the input array are negative.
* In that case, the least value among all elements is the maximum sum with
* subarray length = 1.
* @author [Abhijeet Tiwari](https://github.com/thisabhijeet)
*/
#include <array>
#include <cassert> // for assert
#include <climits> // for INT_MIN value
#include <iostream> // for io operations
/** max_subarray_sum function
* \param arr input array
* \param length length of the input array
* \returns maximum contiguous subarray sum
*/
template <std::size_t SIZE>
int max_subarray_sum(std::array<int, SIZE> arr, int length) {
int current_max = INT_MIN, current_sum = 0;
for (int i = 0; i < length; i++) {
current_sum = current_sum + arr[i];
if (current_max < current_sum) {
current_max = current_sum;
}
if (current_sum < 0) {
current_sum = 0;
}
}
return current_max;
}
/**
* @brief Self-test implementations
* @returns void
*/
static void test() {
std::array<int, 4> arr = {1, 2, 3, 4};
std::array<int, 5> arr1 = {-1, -2, -4, -6, 7};
assert(max_subarray_sum(arr, 4) == 10);
assert(max_subarray_sum(arr1, 5) == 7);
std::cout << "all test cases passed!";
}
/** main function */
int main() {
// Below is the code for accepting array from user and then
// calling the function for the required output.
// It has been commented for now so that the test() function can run
// and test cases can be verified.
// code for accepting array from user starts
// std::size_t n; // variable for length of input array
// std::cout << "Enter length of the array: ";
// std::cin >> n;
// std::array<int, 100> arr = {0};
// // we need to give a constant in size. Hence we have allocated 100
// for now.
// for (int i = 0; i < n; i++)
// taking input of each element of the array
// {
// std::cin >> arr[i];
// }
// for (int i = 0; i < 100; i++)
// taking input of each element of the array
//
// {
// std::cout << arr[i] << std::endl;
// }
// int max_sum = max_subarray_sum(arr, n);
// std::cout << "Maximum contiguous sum for this array is : " << max_sum
// << std::endl;
// code for accepting array from user ends
test();
return 0;
}