将一个任意输入的10进制数转化为16进制形式输出

//将一个任意输入的10进制数转化为16进制形式输出
#include<stdio.h>
#define MAXSIZE 11

void ten20x(unsigned int a,char *p)
{
    int i;
    int j = 2;
    int sum = 0;
    int count = 0;
    unsigned int mask = 0x80000000;

    *(p + 0) = '0';
    *(p + 1) = 'X';
    *(p + 10) = '\0';
    while(count < 8)
    {
        for(i = 0; i < 4; i++)
        {
            if((a & mask) == mask)
     {
         sum = sum * 2 + 1;
     }
            else
     {
         sum = sum * 2 + 0;
     }
     a = a << 1;
        }
        if(sum < 10)
        {
            *(p + j) = sum + '0';
     j++;
        }
        else
        {
            *(p + j) = sum - 10 + 'a';
     j++;
        }
 sum = 0;
 count++;
    }
 
}

int main()
{
    unsigned int ver = 0;

    char sixtn[MAXSIZE];

    printf("please input a num \n");
    scanf("%d",&ver);
    ten20x(ver,sixtn);
    printf("%d 的16进制为 %s\n",ver,sixtn);
    return 0;
}