Update a1/program.c

a1/program.c

@@ -39,7 +39,7 @@ int main() {
         } else if (isClosing(current)) {
             if (top == -1) {
                 printf("Unexpected closing bracket '%c' in %d.\n", current, i);
-                return 1;
+                return 0;
             }
             if (!isMatching(stack[top], current)) {
                 printf("Crossed bracket '%c' in %d , expected \n", current, i);