짝지어 제거하기

Java

import java.util.*;
class Solution
{
    public int solution(String s){
        if(s.length() % 2 == 1)
            return 0;
        
        Stack<Integer> stack = new Stack();
        
        int before = 0;
        int i = 0;
        while(i < s.length()){
            if(before == s.charAt(i)){
                stack.pop();
            }else{
                stack.push((int)s.charAt(i));
            }
            if(stack.size() > 0)
                before = stack.peek();
            else
                before = 0;
            i++;
        }
        
        
        
        return stack.size() == 0 ? 1 : 0;
    }
    
    
    /*효율성 탈락
    public int solution(String s)
    {
        int answer = 0;
        StringBuffer st = new StringBuffer(s);

        for(int i = st.length() - 1; i > 0;){
            if (st.charAt(i - 1) == st.charAt(i)){
                st = st.replace(i - 1, i + 1, "");
                i = st.length() - 1;
            }else{
                i--;
            }
        }
        
        return st.length() == 0 ? 1: 0;
    }*/
}

Python

def solution(s):
    answer = 0

    if len(s) % 2 == 1: return 0
    
    i = 1
    before = s[0]
    stack = list()
    stack.append(before)
    
    while i < len(s):
        if before == s[i]:
            stack.pop()
        else:
            stack.append(s[i])
        if len(stack) > 0:
            before = stack[-1]
        else:
            before = ''
        i += 1

    return 1 if len(stack) == 0 else 0