844.cpp

class Solution {
public:
    bool backspaceCompare(string S, string T) {
        
        stack<char>S1;
        stack<char>S2;
        
        int i=0;
        int j=0;
        
        while(i<S.length())
        {   
            if(!S1.empty() && S[i]=='#')
            {
                S1.pop();
            }
            if(S[i]!='#')
            {
                S1.push(S[i]);
            }
            
                i++;
        }
        
        while(j<T.length())
        {   
            if(!S2.empty() && T[j]=='#')
            {
                S2.pop();
            }
            if(T[j]!='#')
            {
                S2.push(T[j]);
            }
            
                j++;
        }
        
        return (S1==S2);
        
    }
};