题解 | #合法的括号字符串#

import java.util.*;


public class Solution {
    /**
     * 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
     *
     *
     * @param s string字符串
     * @return bool布尔型
     */
    public boolean isValidString (String s) {
        // write code here
        int count = 0;
        int start = 0;
        MyStack stack = new MyStack(s.length());
        for (int i = 0; i < s.length(); i++) {
            char current = s.charAt(i);
            switch (current) {
                case '(':
                    stack.pop(current,count);
                    break;
                case ')':
                    if (!stack.isEmpty()) {
                        stack.push();
                        stack.pushStart();
                    } else {
                        count--;
                        if (count <0)
                            return false;
                    }
                    break;
                case '*':
                    count++;
                    break;
                default:
                    break;
            }

            if (i == s.length() - 1 && !stack.isEmpty()) {
                int rightStart = count - stack.getStar();
                if(rightStart<stack.getSize())
                    return false;
               
            }

        }
            
             return true;
                         
    }




class MyStack {
    int maxSize;
    char[] chars;
    int pos = -1;
    int spos = -1;
    int leftStars[];

    MyStack(int max) {
        maxSize = max;
        chars = new char[maxSize];
        leftStars = new int[maxSize];

    }

    public void pop(char ch,int star) {
        chars[++pos] = ch;
        leftStars[++spos] = star;

    }

    public char push() {

        return chars[pos--];
    }

   public  int pushStart(){

           return leftStars[spos--];
   }

   public int getStar(){
     return leftStars[spos];
   }
    boolean isEmpty() {
        return pos == -1;
    }

    public char peek() {

        return chars[pos];
    }


    public int getPos() {

        return pos;
    }

    public int getSize(){
        return pos+1;
    }
 }
}