回调函数实现计算器

int Add(int x, int y) {
	return x + y;
}
int Sub(int x, int y) {
	return x - y;
}
int Mul(int x, int y) {
	return x * y;
}
int Div(int x, int y) {
	return x / y;
}
void calc(int (*pf)(int, int)) {
	int x = 0, y = 0;
	int ret = 0;
	printf("请输入两个操作数:>");
	scanf("%d%d", &x, &y);
	ret = (*pf)(x, y);
	printf("%d\n", ret);
}
int main() {
	int input = 0;
	do {
		printf("请选择:>");
		scanf("%d", &input);
		switch (input) {
		case 1:
			calc(Add);
			break;
		case 2:
			calc(Sub);
			break;
		case 3:
			calc(Mul);
			break;
		case 4:
			calc(Div);
			break;
		case 0:
			printf("退出计算器\n");
			break;
		default:
			printf("选择错误\n");
			break;
		}
	} while (input);
	return 0;
}

int main() {
	int input = 0;
	printf("请选择:>");
	scanf("%d", &input);
	int x = 0, y = 0;
	int ret = 0;
	int (*pfArr[5])(int, int) = { 0,Add,Sub,Mul,Div };
	if (input == 0) {
		printf("退出计算器\n");
	}
	else if (input >= 1 && input <= 4) {
		printf("请输入两个操作数:>");
		scanf("%d%d", &x, &y);
		ret = pfArr[input](x, y);
		printf("%d\n", ret);
	}
	else {
		printf("选择错误\n");
	}
	return 0;
}