feat: add check_amicable_pair.cpp (#879)

* feat: add check_amicable_pair.cpp * fix: space between else and brace. * fix: spaces between tokens * fix: removed sqrt and test func combined to single * docs: removed wiki link Co-authored-by: Krishna Vedala <7001608+kvedala@users.noreply.github.com> * docs: add markdown syntax for wikipedia link Co-authored-by: Krishna Vedala <7001608+kvedala@users.noreply.github.com> * docs: change brief to details in comment Line 7 Co-authored-by: Krishna Vedala <7001608+kvedala@users.noreply.github.com> * docs: typo fixed Co-authored-by: Krishna Vedala <7001608+kvedala@users.noreply.github.com> * docs: removed extra line Co-authored-by: Krishna Vedala <7001608+kvedala@users.noreply.github.com> * docs: removed copyright Co-authored-by: Krishna Vedala <7001608+kvedala@users.noreply.github.com> * docs: add author name Co-authored-by: Krishna Vedala <7001608+kvedala@users.noreply.github.com> * fix: shortened the code in is_amicable() Co-authored-by: David Leal <halfpacho@gmail.com> * fix: changed is_amicable to are_amicable * docs: cleared unwanted line Co-authored-by: Krishna Vedala <7001608+kvedala@users.noreply.github.com> Co-authored-by: Krishna Vedala <7001608+kvedala@users.noreply.github.com> Co-authored-by: David Leal <halfpacho@gmail.com>
2026-02-03 10:35:34 +08:00 · 2020-06-24 01:03:42 +05:30
parent 7393d88811
commit 1d7a73ea58
1 changed files with 70 additions and 0 deletions
--- a/math/check_amicable_pair.cpp
+++ b/math/check_amicable_pair.cpp
@@ -0,0 +1,70 @@
+/**
+ * 
+ * @file
+ * \brief A C++ Program to check whether a pair of number is [amicable pair](https://en.wikipedia.org/wiki/Amicable_numbers) or not.
+ * 
+ * \details
+ * Amicable Pair are two positive integers such that sum of the proper divisor 
+ * of each number is equal to the other number.
+ * @author iamnambiar
+ */
+#include <iostream>
+#include <cassert>
+
+/**
+ * Function to calculate the sum of all the proper divisor 
+ * of an integer.
+ * @param num First number.
+ * @return Sum of the proper divisor of the number.
+ */
+int sum_of_divisor(int num) {
+    // Variable to store the sum of all proper divisors.
+    int sum = 0;
+    // Below loop condition helps to reduce Time complexity by a factor of square root of the number.
+    for (int div = 2; div * div <= num; ++div) {
+        // Check 'div' is divisor of 'num'.
+        if (num % div == 0) {
+            // If both divisor are same, add once to 'sum'
+            if (div == (num / div)) {
+                sum += div;
+            } else {
+                // If both divisor are not the same, add both to 'sum'.
+                sum += (div + (num / div));
+            }
+        }
+    }
+    return sum + 1;
+}
+
+/**
+ * Function to check whether the pair is amicable or not.
+ * @param x First number.
+ * @param y Second number.
+ * @return `true` if the pair is amicable
+ * @return `false` if the pair is not amicable
+ */
+bool are_amicable(int x, int y) {
+    return (sum_of_divisor(x) == y) && (sum_of_divisor(y) == x);
+}
+
+/**
+ * Function for testing the is_amicable() with 
+ * all the test cases.
+ */
+void test() {
+    // are_amicable(220, 284) returns true.
+    assert(are_amicable(220, 284) == true);
+    // are_amicable(6232, 6368) returns true.
+    assert(are_amicable(6368, 6232) == true);
+    // are_amicable(458, 232) returns false.
+    assert(are_amicable(458, 232) == false);
+}
+
+/**
+ * Main Function
+*/
+int main() {
+    test();
+    std::cout << "Assertion Success." << std::endl;
+    return 0;
+}