C语言进制转换

#include <iostream>
#include <string>
#include <math.h>
using namespace std;
/***
 * 入口参数：(long int)需要转换的数据、(int)需要转换的数据进制、(int)转换后的数据进制 
 * 返回参数：long
***/
long BaseConversion(long _num, int before_base, int rear_base)
{
    long temp = 0;
    //十进制转换为二进制
    if (before_base == 10 && rear_base == 2)
    {
        for (int count = 0; _num != 0; count++)
        {
            temp += (_num % 2) * pow(10, count);
            _num /= 2;
        }
    }
    //二进制转换为十进制
    else if (before_base == 2 && rear_base == 10)
    {
        for (int count = 0; _num != 0; count++)
        {
            temp += (_num % 10) * pow(2, count);
            _num /= 10;
        }
    }
    return temp;
}
int main(int argc, char *argv[])
{
    long num1 = 11111; //31
    int num2 = 23;     //10111
    cout << BaseConversion(num1, 2, 10) << endl;
    cout << BaseConversion(num2, 10, 2) << endl;
    cout << BaseConversion(55, 10, 2) << endl;
    //十进制输出为十六进制推荐使用方法
    printf("%#X\n", BaseConversion(num1, 2, 10));
    return 0;
}

for (int count = 0; _num != 0; count++)
{
  temp += (_num % 2) * pow(10, count);
  _num /= 2;
 }

for (int count = 0; _num != 0; count++)
{
  temp += (_num % 10) * pow(2, count);
   _num /= 10;
}