十进制转化为七进制

迭代法：

void ten_to_seven(int num)
{
   	int tmp,res=0,n=1;
	do {
        	tmp = num % 7;
       	        num /= 7;
        	res += tmp * n;
        	n *= 10;
    	}while (num > 0);

    printf("%d\n", res);
}

 

递归法：

void ten_to_seven(int number)
{
	int a;
	if(number!=0){
		a=number%7;
		number=number/7;
		ten_to_seven(number);
		printf("%d",a); 
	}
}