写一个递归函数DigitSum(n)，输入一个非负整数，返回组成它的数字之和(C语言)

#include<stdio.h>#include<Windows.h>int DigitSum(unsigned int n){int sum = 0;if(n)sum=(n%10)+(DigitSum(n/10));return sum;}int main(){unsigned int n = 0;while(1){printf("请输入一个非负整数：\n");    scanf("%d",&n);printf("%d\n",DigitSum(n));    }system("pause");return 0;}

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