Recursively implements the sum of each bit of an integer

topic

Write a recursive function DigitSum(n) that takes a non-negative integer and returns the sum of the numbers that make it up. For example, calling DigitSum(1729) should return 1+7+2+9, whose sum is 19

#include<stdio.h>
#include<stdlib.h>
int sum_bit(int num)
{
    if(num==0)
        return 0;
    else
        return num%10+sum_bit(num/10);
}
int main()
{
    int num=0;
    printf("请输入一个整数：");
    scanf("%d",&num);
    printf("%d\n",sum_bit(num));
    system("pause");
    return 0;
}

operation result