1047. Remove All Adjacent Duplicates In String optimized

class Solution {
public:
    string removeDuplicates(string s) {
        
        string ans;
        for(int i=0; i<s.size(); i++){
            if(ans.size() && ans.back()== s[i]) ans.pop_back();
            else ans.push_back(s[i]);
        }
        return ans;
    }
};