Linux下的c程式—數組、malloc

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

struct flex
{
    int count;
    double average;
    double scores[];   // 定義可伸縮的數組
}; // 聲明結構體

void showFlex(const struct flex * p);   //定義函數

int main(void)
{
    struct flex * pf1, *pf2;  

    int n = 5;  // 變數的初始化
    int i;
    int tot = 0;
    // allocate space for structure plus array
    pf1 = malloc(sizeof(struct flex) + n * sizeof(double)); //根據數組的大小申請地址空間
    pf1->count = n;
    for (i = 0; i < n; i++)
    {
        pf1->scores[i] = 20.0 - i;  //給數組元素賦值
        tot += pf1->scores[i]; 
    }
    pf1->average = tot / n;
    showFlex(pf1);

    n = 9;   
    tot = 0;
    pf2 = malloc(sizeof(struct flex) + n * sizeof(double));
    pf2->count = n;
    for (i = 0; i < n; i++)
    {
        pf2->scores[i] = 20.0 - i/2.0;
        tot += pf2->scores[i];
    }
    pf2->average = tot / n;
    showFlex(pf2); 
    free(pf1); //釋放地址空間
    free(pf2);
    return 0;
}

void showFlex(const struct flex * p)   //遍曆結構體中的數組並列印平均值
{
    int i;
    printf("Scores : ");
    for (i = 0; i < p->count; i++)
        printf("%g ", p->scores[i]);
    printf("\nAverage: %g\n", p->average);
}