力扣-20.有效的括号

题目链接

20.有效的括号

class Solution {public boolean isValid(String s) {Stack<Character> stack = new Stack<>();for (int i = 0; i < s.length(); i++) {if (s.charAt(i) == '(' || s.charAt(i) == '{' || s.charAt(i) == '[') {stack.push(s.charAt(i));} else {if (stack.isEmpty())return false;char top = stack.pop();if ((s.charAt(i) == ']' && top != '[') || (s.charAt(i) == ')' && top != '(') || (s.charAt(i) == '}' && top != '{')) {return false;}}}return stack.isEmpty();}
}

小结：秒了！！！