题解 | 牛牛的数学作业

#include <stdio.h>

int main() {
    int T = 0;
    scanf("%d", &T);
    int arr[100][10000] = {0};
    int a[100] = { 0 };//极差
    double b[100] = { 0.0 };//方差
    int i = 0;
    int n = 0;
    for (i = 0; i < T; i++) {
        scanf("%d", &n);
        int j = 0;
        double sum1 = 0;
        int max = 0;
        int min = 100000;
        for (j = 0; j < n; j++) {
            scanf("%d", &arr[i][j]);
        }
        for (j = 0; j < n; j++) {
            if (arr[i][j] > max) {
                max = arr[i][j];
            }
            if (arr[i][j] < min) {
                min = arr[i][j];
            }
            sum1 += arr[i][j];
        }
        a[i] = max - min;
        double avg = sum1 / n;
        double sum2 = 0;
        for (j = 0; j < n; j++) {
            sum2 = sum2 + (arr[i][j] - avg) * (arr[i][j] - avg);
        }
        b[i] = sum2 / n;
    }
    for (i = 0; i < T; i++) {
        printf("%d %.3lf\n", a[i], b[i]);
    }
    return 0;
}