update documentation for gcd_of_n_numbers

others/gcd_of_n_numbers.cpp

@@ -1,23 +1,42 @@
-// This program aims at calculating the GCD of n numbers by division method
+/**
+ * @file
+ * @brief This program aims at calculating the GCD of n numbers by division
+ * method
+ *
+ * @see ../math/greatest_common_divisor.cpp
+ * greatest_common_divisor_euclidean.cpp
+ */
 #include <iostream>
 
-int main() {
-    int n;
-    std::cout << "Enter value of n:" << std::endl;
-    std::cin >> n;
-    int *a = new int[n];
-    int i, j, gcd;
-    std::cout << "Enter the n numbers:" << std::endl;
-    for (i = 0; i < n; i++) std::cin >> a[i];
-    j = 1;  // to access all elements of the array starting from 1
-    gcd = a[0];
+/** Compute GCD using division algorithm
+ *
+ * @param[in] a array of integers to compute GCD for
+ * @param[in] n number of integers in array `a`
+ */
+int gcd(int *a, int n) {
+    int j = 1;  // to access all elements of the array starting from 1
+    int gcd = a[0];
     while (j < n) {
         if (a[j] % gcd == 0)  // value of gcd is as needed so far
             j++;              // so we check for next element
         else
             gcd = a[j] % gcd;  // calculating GCD by division method
     }
-    std::cout << "GCD of entered n numbers:" << gcd;
+    return gcd;
+}
+
+/** Main function */
+int main() {
+    int n;
+    std::cout << "Enter value of n:" << std::endl;
+    std::cin >> n;
+    int *a = new int[n];
+    int i;
+    std::cout << "Enter the n numbers:" << std::endl;
+    for (i = 0; i < n; i++) std::cin >> a[i];
+
+    std::cout << "GCD of entered n numbers:" << gcd(a, n) << std::endl;
+
     delete[] a;
     return 0;
 }