无符号数转字符串

源代码

void ultoa(unsigned long num, char *str, char radix)
{
    char index[] = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";
    int i = 0, j = 0, k = 0;

    do
    {
        str[i++] = index[num % radix];
        num /= radix;
    } while (num);
    char temp;
    for (j = k; j <= (i - 1) / 2; j++)
    {
        temp = str[j];
        str[j] = str[i - 1 + k - j];
        str[i - 1 + k - j] = temp;
    }
    str[i] = '\0';
}

例子

char str_tmp[16] = {0};
ultoa(322,str_tmp,10);