《C语言入门经典》习题7.4 （原创，仅用于学习讨论）

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

int main(void)
{

    int i, j, n;
    double sum, **day = NULL;

    printf("请输入你要计算的天数：");
    scanf_s(" %d", &n , sizeof(int));
    printf("\n\n");
    day = calloc(n, sizeof(double*));

    for (i = 0; i < n; ++i)
    {
        *(day + i) = calloc(6, sizeof(double));
        sum = 0.0;
        for (j = 0; j < 6; ++j)
        {
            printf("请输入第%d天第%d个温度：", i + 1, j + 1);
            scanf_s(" %lf", day[i] + j);
            sum += day[i][j];
        }
        printf("第%d天的六个温度为：", i + 1);
        for (j = 0; j < 6; ++j)
            printf("%lf ", day[i][j]);
        printf("\n第%d天的平均温度为：%.1lf\n\n\n", i + 1, sum / 6.0);
    }

    for (i = 0; i < n; ++i)
        free(day[i]);
    free(day);
    system("pause");
    return 0;
}