题解 | #括号序列#

import java.util.*;


public class Solution {
    /**
     * 
     * @param s string字符串 
     * @return bool布尔型
     */
    public boolean isValid (String s) {
        // write code here
        int n = s.length();
        if (n % 2 == 1) {
            return false;
        }
        Deque<Character> stack = new LinkedList<>();
        HashMap<Character,Character> map = new HashMap<Character,Character>(){{
            put(']','[');
            put(')','(');
            put('}','{');
        }};

        for(int i = 0 ; i < s.length(); i++){
            if(map.containsKey(s.charAt(i))){
                if(!stack.isEmpty() && stack.peek() == map.get(s.charAt(i))){
                    stack.pop();
                }else{
                    return false;
                }
            }else{
                stack.push(s.charAt(i));
            }
        }
        return stack.isEmpty();

    }
}