题解 | 牛牛的数学作业

#include <stdio.h>
#include<math.h>
int main() {
    int T;
    scanf("%d",&T);
    while(T--){
        int a;
        scanf("%d",&a);
        long long np1[10001];
        long long m;
        scanf("%lld",&m);
        np1[1]=m;
        long long max=np1[1];
        long long min=np1[1];
        long long sum=m;
        for(int i=2;i<=a;i++){
            scanf("%lld ",&m);
            np1[i]=m;
            if(np1[i]>max){
                max=np1[i];
            }
            if(np1[i]<min){
                min=np1[i];
            }
            sum=sum+np1[i];
        }
        printf("%lld ",max-min);
        double avg = (double)sum / a;
        double variance_accum = 0.0;
        for(int i=1;i<=a;i++){
            double diff = np1[i] - avg;
            variance_accum += diff * diff;
        }
        double fangcha=variance_accum/a;
        printf("%.3f\n",fangcha);
    }
    return 0;
}