编辑代码

#include <stdio.h>

int sum(int arr[],int len){
    if(len==0){
        return 0;
    }
    return sum(arr,len-1)+arr[len-1];
}

int main () {
    int arr1[]={3,4,5};
    printf("3+4+5 = %d\n",sum(arr1,3));

    int arr2[]={0,0,0};
    printf("0+0+0 = %d\n",sum(arr2,3));

    int arr3[]={};
    printf("%d\n",sum(arr3,0));

    return 0;
}