#include <stdio.h>

#define uint unsigned int
#define MAX_SIZE 1024    //数组长度

 //十进制数字转换成十六进制字符串
char * num2hex(uint num)
{
    int i;
    uint tmp;

    uint mask = 0xf;            //掩码0x 0000 000f
    
    static char hex[MAX_SIZE];  //存储十六进制字符串

    hex[0] = '0';               //前两位固定不变，为0x
    hex[1] = 'x'; 
    
    //为其余元素赋值
    for(i = 9; i >= 2; i--)
    {
        tmp = num & mask;
	    hex[i] = (tmp >= 10) ? ((tmp - 10)  + 'a') : (tmp + '0'); 
	    num  = num >> 4;
    }

    return hex;
}

int main()
{
    uint num;
    
    char * tmp;

    printf("Please input a number:");
    scanf("%d", &num);

    tmp = num2hex(num);
    printf("%d to hex is %s\n", num, tmp);
    
    return 0;
}