mirror of
https://github.com/TheAlgorithms/C-Plus-Plus.git
synced 2026-02-04 02:56:40 +08:00
0d766b0f8a
* chore: add cache and build comment to git ignore
* fix: add cmakelists to dynamic programming
* fix: add cmakelists to greedy_algorithms
* fix: add cmakelists to operations_on_datastructures
* fix: add cmakelists to range_queries
* fix: add `dynamic_programmin`, `greedy_algorithms`, `range_queries` and `operations_on_datastructures` subdirectories to cmakelists.txt
* fix: init of transform_reduce in dynamic_programming
* fix: add an include for functional in catalan_numbers
* chore: bump CXX standard to 20
* revert: bump CXX standard to 20
* chore: bump c++ version to 17 and add justification
Arm supports c++ 17
Esp32 supports c++ 23
decision was made to be 17 because it seemed to offer the best combatability
* fix: compilation error in catalan numbers
* fix: add <set> header to longest increasing subsequence nlogn
* fix: add cmath & algorithm header to mo.cpp
* fix: remove register key word from fast integer
* fix: replace using namespace std with std::cin and std::cout
* docs: typo in c++17
* fix: memory leak in bellman_ford
* fix: typo in bellman_ford
* fix: typo in word_break
* fix: dynamic array in coin_change
* fix dynamic array in egg_dropping puzzle
* chore: remove unnecessary comment
* fix: add vla to be an error
* chore: add extra warnings
* fix: use add_compile options instead of set()
* fix: compile options are not strings
* fix: vla in floyd_warshall
* fix: vla in egg_dropping_puzzel
* fix: vla in coin_change
* fix: vla in edit_distance
* fix: vla in floyd_warshall
* feat: remove kadane and replace it with kadane2
* fix: vla in longest_common_subsequence
* fix: int overflow in floyd_warshall
* fix: vla in lisnlogn
* fix: use const vector& instead of array
* fix: use dynamic array instead of vla in knapsack
* fix: use of and in msvc is unsupported by default adding permissive flag fixes it
* test: make executables the tests themselves
* Revert "test: make executables the tests themselves"
This reverts commit 7a16c31c4e.
* fix: make dist constant in print
* fix: namespace issue in unbounded_0_1
* fix: include cstdint to fix compilation
94 lines
2.7 KiB
C++
94 lines
2.7 KiB
C++
/**
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* @file
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* @brief Checks whether a number is an [Armstrong
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* Number](https://en.wikipedia.org/wiki/Narcissistic_number) or not.
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*
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* @details
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* An Armstrong number is a number that is the sum of its own digits each raised
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* to the power of the number of digits. For example: 153 is an Armstrong number
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* since 153 = 1^3 + 5^3 + 3^3.
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*
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* A few examples of valid armstrong numbers:
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* 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 153, 370, 371, 407, 1634, 8208, 9474, 54748,
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* 92727, 93084.
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*
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* Armstrong numbers are also known as Narcissistic Numbers, as stated in
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* Wikipedia.
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*
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* @author [Shivam Singhal](https://github.com/shivhek25)
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* @author [David Leal](https://github.com/Panquesito7)
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*/
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#include <cassert> /// for assert
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#include <cmath> /// for std::pow
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#include <iostream> /// for IO operations
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/**
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* @namespace
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* @brief Dynamic Programming algorithms
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*/
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namespace dynamic_programming {
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/**
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* @brief Checks if the given number is armstrong or not.
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* @param number the number to check
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* @returns false if the given number is NOT armstrong
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* @returns true if the given number IS armstrong
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*/
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template <typename T>
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bool is_armstrong(const T &number) {
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int count = 0, temp = number, result = 0, rem = 0;
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// Count the number of digits of the given number.
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// For example: 153 would be 3 digits.
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while (temp != 0) {
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temp /= 10;
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count++;
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}
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// Calculation for checking of armstrongs number i.e.
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// in an n-digit number sum of the digits is raised to a power of `n` is
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// equal to the original number.
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temp = number;
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while (temp != 0) {
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rem = temp % 10;
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result += static_cast<T>(std::pow(rem, count));
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temp /= 10;
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}
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if (result == number) {
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return true;
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} else {
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return false;
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}
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}
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} // namespace dynamic_programming
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/**
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* @brief Self-test implementations
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* @returns void
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*/
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static void tests() {
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assert(dynamic_programming::is_armstrong(153) == true);
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assert(dynamic_programming::is_armstrong(1) == true);
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assert(dynamic_programming::is_armstrong(0) == true);
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assert(dynamic_programming::is_armstrong(370) == true);
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assert(dynamic_programming::is_armstrong(1634) == true);
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assert(dynamic_programming::is_armstrong(580) == false);
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assert(dynamic_programming::is_armstrong(15) == false);
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assert(dynamic_programming::is_armstrong(1024) == false);
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assert(dynamic_programming::is_armstrong(989) == false);
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assert(dynamic_programming::is_armstrong(103) == false);
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std::cout << "All tests have successfully passed!\n";
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}
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/**
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* @brief Main function
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* @returns 0 on exit
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*/
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int main() {
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tests(); // run self-test implementations
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return 0;
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}
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