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
        Stack<Character> stack=new Stack<Character>();
        int i=0;
        while(i<s.length())
        {
            char cmp=s.charAt(i);
            if(cmp=='(' || cmp=='{'||cmp=='[') {stack.push(cmp);i++;continue;}
            else if(!stack.isEmpty() &&cmp==')' && stack.peek()=='(')
            {
                stack.pop(); i++;continue;
            }
            else if(!stack.isEmpty()&&cmp=='}' && stack.peek()=='{')
            {
                stack.pop(); i++;continue;
            }
            else if(!stack.isEmpty()&&cmp==']' && stack.peek()=='[')
            {
                stack.pop(); i++;continue;
            }else{
                return false;
            }
        }
        return stack.isEmpty() ? true: false;
    }
}