题解 | #有效括号序列#

import java.util.*;


public class Solution {
    /**
     *
     * @param s string字符串
     * @return bool布尔型
     */
    public boolean isValid (String s) {
        Stack<Character> stack = new Stack<>();
        Map<Character, Character> map = new HashMap<>();
        map.put(')', '(');
        map.put(']', '[');
        map.put('}', '{');
        for (int i = 0; i < s.length(); i++) {
            char c = s.charAt(i);
            Character l = map.get(c);
            if(l!=null){
                if(stack.isEmpty() || stack.pop() != l){
                    return false;
                }
            } else {
                stack.push(c);
            }
        }
        return stack.isEmpty();
    }
}