Greatest common divisor.

misc/GCD.c

@@ -0,0 +1,20 @@
+#include <stdio.h>
+
+// Euclid's algorithm
+int GCD(int x, int y) {
+    if (x == y || y == 0)
+        return x;
+    if (x == 0)
+        return y;
+    if (x > y)
+        return GCD(x-y, y);
+    else
+        return GCD(x, y-x);
+}
+
+int main() {
+    int a, b;
+    printf("Input two numbers:\n");
+    scanf("%d %d", &a, &b);
+    printf("Greatest common divisor: %d\n", GCD(a, b));
+}