Redundant Braces (InterviewBit)

int Solution::braces(string A) {
    stack<int> s;
    for(int i = 0; i < A.length(); i++) {
        if(A[i] == '(' || A[i] == '+' || A[i] == '-' || A[i] == '*' || A[i] == '/')
        s.push(A[i]);
        else if(A[i] == ')') {
            if(s.top() == '(')
                return 1;
            else {
                while(s.top() != '(') {
                    s.pop();
                }
                s.pop(); 
            }
        }
    }
    return 0;
}