分配一个大 (5000+) 数组 [英] Allocating A Large (5000+) Array

问题描述

我正在开发一个应用程序，输入的数据有三种可能的大小:

I am working on an application were there are three possible sizes for the data entered:

• 小:1000 个元素
• 中 = 5000 个元素
• 大= 500,000 个元素

问题是我无法分配大数组.似乎不接受大于 5000 的大小.

The problem is that I can't allocate the large array. It seems that a size larger than 5000 is not accepted.

执行以下操作时出现运行时错误:

I get a run time error when I do the following:

long  size=1000;
char ch;
int arr[size];
ch=getch();

if(ch==..)
  size=...;

1000 和 5000 的大小似乎工作正常，但如何以这种方式制作大小为 500k 的数组?

Sizes of 1000 and 5000 seem to work fine, but how can I make an array of size 500k in this way?

推荐答案

可以在堆上分配这么大的数组:

You can allocate such a big array on the heap:

int *arr;
arr = malloc (sizeof(int) * 500000);

不要忘记检查分配是否成功(如果不是 - malloc 返回 NULL).

Don't forget to check that allocation succeded (if not - malloc returns NULL).

正如 pmg 所提到的 - 因为这个数组不在堆栈中，所以一旦你完成了它，你必须释放它.

And as pmg mentioned - since this array is not located in the stack, you have to free it once you finished working with it.

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