USACO 1.2 Palindromic Squares

/*
ID: aznfy1
PROG: palsquare
LANG: C++
*/

#include<stdio.h>
#include<string.h>
#include<iostream>
using namespace std;
int num[20];
int len;int flag;
void change(int x,int b)
{
    int i=0;
    while(x!=0)
    {
        num[i]=(x%b);
        x=x/b;
        i++;
    }
    len=i;
}
int main()
{
    freopen("palsquare.in","r",stdin);
    freopen("palsquare.out","w",stdout);
    int n;
    while(cin>>n)
    {
        for(int i=1;i<=300;i++)
        {
            flag=1;
            change(i*i,n);
            for(int i=0;i<len/2;i++)
            {
                if(num[len-i-1]!=num[i])
                {
                    flag=0;
                    break;
                }
            }
            if(flag)
            {
               change(i,n);
               for(int i=len-1;i>=0;i--)
               {
                if(num[i]==10)
                {cout<<'A';continue;}
                if(num[i]==11)
                {cout<<'B';continue;}
                if(num[i]==12)
                {cout<<'C';continue;}
                if(num[i]==13)
                {cout<<'D';continue;}
                if(num[i]==14)
                {cout<<'E';continue;}
                if(num[i]==15)
                {cout<<'F';continue;}
                if(num[i]==16)
                {cout<<'G';continue;}
                if(num[i]==17)
                {cout<<'H';continue;}
                if(num[i]==18)
                {cout<<'I';continue;}
                if(num[i]==19)
                {cout<<'J';continue;}
                cout<<num[i];
               }
               cout<<' ';
               change(i*i,n);
               for(int i=0;i<len;i++)
               {
                   if(num[i]==10)
                {cout<<'A';continue;}
                if(num[i]==11)
                {cout<<'B';continue;}
                if(num[i]==12)
                {cout<<'C';continue;}
                if(num[i]==13)
                {cout<<'D';continue;}
                if(num[i]==14)
                {cout<<'E';continue;}
                if(num[i]==15)
                {cout<<'F';continue;}
                if(num[i]==16)
                {cout<<'G';continue;}
                if(num[i]==17)
                {cout<<'H';continue;}
                if(num[i]==18)
                {cout<<'I';continue;}
                if(num[i]==19)
                {cout<<'J';continue;}
                   cout<<num[i];
               }
               cout<<endl;
            }
        }
    }
    return 0;
}