题解 | #密码截取#

//我明明是暴力解，却居然超过100%用JAVA提交的人，第一次超过100%。运行时间12ms
import java.util.*;
import java.io.*;
public class Main{
    public static void main(String[] args) throws IOException{
        BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
        String s=null;
        while((s=br.readLine())!=null){
            char[] chars=s.toCharArray();
            int max=0;
            int count=0;
            int a=0;
            int countsiii=0;
            int flag=0;
            int count1=1;
            int max1=0;
            for(int i=0;i<chars.length-1;i++){
                //count1=1;
                if(chars[i]==chars[i+1]){ count1++;if(max1<count1) max1=count1;}
                else count1=1;
            }
            //System.out.println(max1);
            
            for(int i=0;i<chars.length-1;i++){
                count=0;
                if(i>=1&&chars[i]==chars[i-1]&&chars[i]==chars[i+1]&&max1>=3&&max1%2==1){countsiii=i-1;flag=3;}
                else if(chars[i]==chars[i+1]) {countsiii=i;flag=2;}
                else {countsiii=i-1;flag=3;}
                for(int j=i+1;j<=chars.length-1;j++){
                    if(countsiii>=0&&chars[countsiii]==chars[j]){
                        count++;countsiii--;
                        if(flag==2){
                            if(max<2*count){
                                max=2*count;
                        }
                        }
                        if(flag==3){
                            if(max<2*count+1){
                                max=2*count+1;
                        }
                        }
                        
                    }
                    else break;
                }
            }
            System.out.println(max);
        }
    }
}