题解 | #括号序列#

java代码

 public boolean isValid (String s) {
        // write code here
        Stack<Character> stack = new Stack<Character>();
        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.empty())
                    return false;
                switch (s.charAt(i)){
                    case ']':if (stack.pop() != '[') return false;break;
                    case '}':if (stack.pop() != '{') return false;break;
                    case ')':if (stack.pop() != '(') return false;break;
                    default:break;
                }
            }
        }
        if (stack.empty()){
            return true;
        }
        return false;
    }