int 转 string 输出 (不用库函数)

#include "stdafx.h"
#include <iostream>
#include <stdio.h>


using namespace std;


void testFormat(int number);
int intToStr(int number, char** szBuffer);
int reverseStr(char** szBuffer);


int _tmain(int argc, _TCHAR* argv[])
{
testFormat(123);
testFormat(123456789);
testFormat(-369542);


system("pause");
return 0;
}


void testFormat(int number)
{
 char buf[50];
 char * b = buf;
 if(intToStr(number,&b) == 0){
  printf("\nint to string success! %d --> \"%s\"\n",number,b);
 }
 else
 {
  printf("\nint to string fail! %d --> \"%s\"\n",number,b);
 }
}


/*
funcation: format int to string
input : number
output: ** szBuffer
return 0 success, -1 fail
*/
int intToStr(int number, char ** szBuffer)
{
int iRet = -1;
if (NULL == *szBuffer)
goto RETURN;


char * buf = *szBuffer;


int num1 = 0, num2 = number;


//如果是负数，先转换为正数
num2 = number > 0 ? number : (number * -1);


//将数字转换为 char
do 
{
num1 = num2 % 10;
*buf = num1 + '0';


buf++;
num2 = num2 / 10;
} while (num2 != 0);


if(0 > number)//负数
{
*buf = '-';
buf++;
}
*buf = '\0';


iRet = reverseStr(szBuffer);


RETURN:
return iRet;
}


/*
funcation : reverse string
intput : ** szBuffer
return 0 succes, -1 fail
*/
int reverseStr(char** szBuffer)
{
int iRet = -1;


if(NULL == *szBuffer)
goto RETURN;


//将转换的字符串逆序
char * p1 = *szBuffer;
char * p2 = p1;


while (*p2++ != '\0');//将p2 指向字符串尾部


p2--;
p2--;


while (p2 > p1)
{
*p1 = *p1 + *p2;
*p2 = *p1 - *p2;
*p1 = *p1 - *p2;


p1++;
p2--;
}


iRet = 0;


RETURN:
return iRet;
}