OJ Board

I don't know what I wrong

I only check the substring's length is 3 ans 4.

#include <iostream>
#include <cstring>
#include <string>
#include <vector>
#include <algorithm>

using std::find ;
using std::vector ;
using std::string ;
using std::cin ;
using std::cout ;
using std::endl ;

bool is_palin ...

I find all I cound find case , including 111 111...etc

But I also got WA

Why?
Here is my code...
#include <iostream>
#include <vector>
#include <algorithm>
#include <cmath>
#include <string>
using namespace std ;
int main(){
int set ;
cin >> set ;
for( int Si = 1 ; Si <= set ; Si ...