关于用递归将10进制数转换成R(2-16)进制数的一种简单算法：
int print(int x,int y)
{
if(x>=y)
{
print(x/y,y);
}
switch(x%y)
{
case 0:
case 1:
case 2:
case 3:
case 4:
case 5:
case 6:
case 7:
case 8:
case 9:printf("%d",x%y);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;
default :break;
}
}

#include<stdio.h>
int main()
{
int N=0;
int R=0;
scanf("%d%d",&N,&R);
print(N,R);
return 0;
}