Added GCD_Calculate.cpp

C++/GCD_Calculate.cpp

@@ -0,0 +1,21 @@
+#include <iostream>
+using namespace std;
+
+int main()
+{
+    int n1, n2;
+
+    cout << "Enter two numbers: ";
+    cin >> n1 >> n2;
+
+    while(n1 != n2)
+    {
+        if(n1 > n2)
+            n1 -= n2;
+        else
+            n2 -= n1;
+    }
+
+    cout << "HCF = " << n1;
+    return 0;
+}