[C语言] 内存空间

内存空间

柔性数组

#define _CRT_SECURE_NO_WARNINGS 1
#include <stdio.h>
#include <stdlib.h>
struct S    //柔性数组
{
  int a ;
  int arr[];   //大小未知
};

int main()
{
  
  struct S* ps = (struct S*)malloc(sizeof(struct S) + 10 * sizeof(int));
  ps->a = 10;
  int i = 0;
  for (i = 0; i < 10; i++)
  {
    ps->arr[i] = i;
  
  }
  //增容
  struct S* ptr = (struct S*)realloc(ps, sizeof(struct S) + 20 * sizeof(int));
  if (ptr != NULL)
  {
    ps = ptr;
  }
  //使用


  //释放
  free(ps);
  ps = NULL;
  return 0;
}