//柔性数组的使用
#include<stdio.h>
#include<stdlib.h>
#include<errno.h>
struct s
{int i;int a[];
};
int main()
{struct s* ps = (struct s*)malloc(sizeof(struct s) + 20 * sizeof(int));if (ps == NULL){perror("malloc");return 1;}//使用这块空间ps->i = 100;int j = 0;for (j = 0; j < 20; j++){ps->a[j] = j + 1;}//调整ps指向空间的大小struct s* str = (struct s*)realloc(ps, sizeof(struct s) + 40 * sizeof(int));if (str != NULL){ps = str;str = NULL;}//使用空间后面开辟的40个字节,打印出来for (j = 0; j < 40; j++){ps->a[j] = j + 1;}for (j = 0; j < 40; j++){if (j % 10 == 0){printf("\n");}printf("%d  ", ps->a[j]);}//释放空间free(ps);ps = NULL;return 0;
}

输出结果：