findout braket CBOSS

#include <iostream>
#include <string>
#include <stack>

using namespace std;

int main() {
    std::stack<int> temp;
    const std::string str("(x+y)*x + x * (12*(x-y))");
    for (std::string::const_iterator iter = str.begin(); iter != str.end(); iter++) {
        if ('(' == *iter) {
            temp.push((int)(iter - str.begin()));
        }
        if (')' == *iter) {
            std::cout<<temp.top()<<" - "<<(int)(iter - str.begin())<<std::endl;
            temp.pop();
        }
    }    

    return 0;
}