String Remove Consecutive Charaa => ""; abbc => "ac"

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

class Solution
{
public:
    string uniqString(string& str) {
        bool flag = false;
        stack<char> stack;
        for (char c : str) {
            if (stack.empty()) {
                stack.push(c);
            } else {
                if (c == stack.top()) {
                    flag = true;
                    //if (stack.size() == 1) {
                    //    stack.pop();
                    //}
                } else {
                    if (flag) {
                        stack.pop();

                    }
                    flag = false;
                    stack.push(c);

                }
                //if (flag) {
                //    stack.pop();
                //}
            }
        }
        if (flag) {
            stack.pop();
        }
        string result;
        while (!stack.empty()) {

            result = stack.top() + result;
            stack.pop();
        }
        return result;
    }

};