#include<stdio.h>
void main()
{
    int i,a;
    scanf("%d",&i);
    while(1)
    {
        a=i%16;
        switch(a)
        {
        case 0:printf("0");break;
        case 1:printf("1");break;
        case 2:printf("2");break;
        case 3:printf("3");break;
        case 4:printf("4");break;
        case 5:printf("5");break;
        case 6:printf("6");break;
        case 7:printf("7");break;
        case 8:printf("8");break;
        case 9:printf("9");break;
        case 10:printf("a");break;
        case 11:printf("b");break;
        case 12:printf("c");break;
        case 13:printf("d");break;
        case 14:printf("e");break;
        case 15:printf("f");break;
        
        }
        i=i/16;
        if(!i)
            break;
   
    }
    printf("H\n");
}


这个函数只能对非负的正整数才有效，负数不行了。