假设 $\text {vr}$ 是一个 $\text {string}$ 类型的 $\text {vector}$ 数组，

$\text {string\_int(string s)}$ 返回将 $s$ 转为数字的结果，rt

	while (!vr.empty()) {
		auto times = find(vr.begin(), vr.end(), "*");
		if (times != vr.end()) {
			int index = times - vr.begin();
			cout << vr[index] << endl;
			int a = string_int(vr[index - 1]);
			int b = string_int(vr[index + 1]);
			vr.erase(vr.begin() + index - 1, vr.begin() + index + 2);
			vr.insert(vr.begin() + index - 1, a * b);
			for (auto i : vr) {
				cout << i << ' ';
			}
			break;
		}
	}