题解 | 牛牛的数学作业

#include <iostream>
#include <math.h>
#include <iomanip>
#include <algorithm>
using namespace std;

int fun_jicha(int* array, int m) {
    return *max_element(array, array + m) - *min_element(array, array + m);
}

double fun_fangcha(int* array, int jicha, int m) {
    double a1 = 0.0;
    double a2 = 0.0;

    for (int i = 0; i < m; i++) {
        a1 += array[i];
    }
    a1 /= m;

    for (int i = 0; i < m; i++) {
        a2 = a2 + pow(array[i] - a1, 2);
    }

    a2 /= m;

    return a2;
}

signed main() {

    int n, jicha;
    double fangcha = 0.0;
    cin >> n;

    for (int i = 0; i < n; i++) {
        int m;
        cin >> m;
        int array[m];
        for (int j = 0; j < m; j++) {
            cin >> array[j];
        }
        cout << fun_jicha(array, m) << " ";
        cout << fixed << setprecision(3) << fun_fangcha(array, fun_jicha(array, m), m) << endl;
    }

    return 0;
}