USACO Section 1.2 Palindromic Squares

/*
ID: lucien23
PROG: palsquare
LANG: C++
*/

#include<iostream>
#include<cstdlib>
#include<fstream>
#include<string>
#include<cmath>
#include<algorithm>
using namespace std;
string num2string(int num,int baseNum);
int main()
{
	ifstream infile("palsquare.in");
	ofstream outfile("palsquare.out");
	if(!infile || !outfile)
	{
		cout<<"file operation failure!"<<endl;
		return -1;
	}

	int baseNum;
	infile>>baseNum;
	for (int i=1;i<=300;i++)
	{
		//GCC里面没有itoa这个函数，得自己写	
		string strNum=num2string(i*i,baseNum);
		string strRevNum=strNum;
		reverse(strRevNum.begin(),strRevNum.end());
		if (strRevNum==strNum)
		{
			outfile<<num2string(i,baseNum)<<" "<<strNum<<endl;
		}
	}

	return 0;
}

string num2string(int num,int baseNum)
{
	int currentNum=num,remainder;
	string strNum="";
	while(currentNum>0)
	{
		remainder=currentNum%baseNum;
		char chNum;
		if(remainder>=10)
			chNum='A'+remainder-10;
		else
			chNum=remainder+'0';
		strNum=chNum+strNum;
		currentNum/=baseNum;
	}
	return strNum;
}