uva_10276 Hanoi Tower Troubles Again!

/*
 Author                             : unlucky_13
 Problem_link                       :
 Category                           :
 Algorithm_Used                     : Backtracking
 */

#include<cstdio>
#include<sstream>
#include<cstdlib>
#include<cctype>
#include<cmath>
#include<algorithm>
#include<set>
#include<queue>
#include<stack>
#include<list>
#include<iostream>
#include<fstream>
#include<numeric>
#include<string>
#include<vector>
#include<cstring>
#include<map>
#include<iterator>
#define LL long long int
//const long long int inf = 2147483647 ;
//const int minx=;
//const int maxn=;

using namespace std;
int res ,peg;
int v[111] ;
bool is_perfect(const int& x) {
    int y = (int) sqrt(x * 1.0);
    return y * y == x;
}

void backtrack(int n){

    bool flag = false ;
    int i = 1 ;
    while(!flag && i<=peg)
    {
        if(v[i]==-1 || is_perfect(v[i]+n)) flag = true ;
        else i++ ;
    }

    if(flag==false)   res = max(res,n-1) ; //no move was possible
    else {
        v[i]=n ;
        backtrack(n+1) ;
    }


}

int main() {

    freopen("C:\\Users\\Mazhar\\Desktop\\Text_Files\\in.txt", "r", stdin);
    int tc ;
    scanf("%d",&tc) ;
    while(tc--)
    {

        res = 0 ;
        scanf("%d",&peg) ;
        for(int i=1;i<=peg;i++) v[i]=-1 ;
        backtrack(1) ;
        printf("%d\n",res) ;
    }



    return 0;

}