题解 | 牛牛的数学作业

#include <stdio.h>
#include <stdlib.h>

int main() {
    int a,b,c;
    scanf("%d",&a);
    for(int i=0;i<a;i++){
       scanf("%d",&b);
       long long *arr = (long long *)malloc(b * sizeof(long long));
       if(arr == NULL){
        return 1;
       }
       long long max,min,sum=0;
       for(int i=0;i<b;i++){
        scanf("%d",&arr[i]);
        sum += arr[i];
        if(i == 0){
            max=arr[0];
            min=arr[0];
        }else{
            if(arr[i]>max){
                max=arr[i];
            }
            if(arr[i]<min){
                min=arr[i];
            }
        }
       }
       long long d = max-min;
       double avg = (double)sum/b;
       double fc_sum = 0.0;
       for(int i=0;i<b;i++){
        fc_sum += (arr[i]-avg)*(arr[i]-avg);
       }
       double fc = fc_sum/b;
       printf("%lld %.3f\n",d,fc);
    }
    return 0;
}

不知道为啥最后写free(arr)会示例第一组不通过