Added GCD example in C

Fix Aniket965#33 Fix Aniket965#166

GCD.c

@@ -0,0 +1,16 @@
+#include <stdio.h>
+int main()
+{
+    int n1, n2, i, gcd;
+    printf("Enter two integers: ");
+    scanf("%d %d", &n1, &n2);
+    for(i=1; i <= n1 && i <= n2; ++i)
+    {
+        if(n1%i==0&&n2%i==0)
+        {
+            gcd = i;
+        }
+    }
+    printf("G.C.D = %d",gcd);
+    return 0;
+}