#include "itos.h"
#include <stack>
#include <cstdlib>

using std::string;
using std::stack;
using std::abs;

string itos(int val)
{
    string answer;
    stack<int> stk;
    int temp;

    if (val < 0)
    {
	answer += "-";
	val = abs(val);
    }

    while (val > 0)
    {
	temp = val % 10;
	stk.push(temp);
	val = val / 10;
    }

    if (stk.empty()) return "0";

    while (!stk.empty())
    {
	temp = stk.top();
	if (temp == 0) answer += '0';
	else if (temp == 1) answer += '1';
	else if (temp == 2) answer += '2';
	else if (temp == 3) answer += '3';
	else if (temp == 4) answer += '4';
	else if (temp == 5) answer += '5';
	else if (temp == 6) answer += '6';
	else if (temp == 7) answer += '7';
	else if (temp == 8) answer += '8';
	else if (temp == 9) answer += '9';
	stk.pop();
    }

    return answer;
}