[C++] 쇠막대기 - 10799

#include <iostream>
#include <string>
using namespace std;

int main()
{
	string str;
	int bar = 0;
	int num = 0;

	getline(cin, str);

	for (int i = 0; i < str.size(); i++)
	{
		if (str[i] == '(')
			bar++;

		else if (str[i] == ')' && str[i - 1] == '(' )
		{
			bar--;
			num += bar;
		}

		else if (str[i] == ')')
		{
			bar--;
			num++;
		}
	}
	cout << num;
	return 0;
}