Dealing with large arrays without getting runtime error

问题

I am getting runtime error when I used array of size 10^5*10^5 (ex. int a[100000][100000]. As this array is consuming more memory, this may be one one of the reasons for runtime error.

How should I declare this array (2D array ex. int a[100000][100000]) so that I can cope with problem of SIGSEGV runtime error?

Please, provide approach to declare such type of array?

回答1:

Three ways to declare the large array int a[100000][100000] are:

1. Make the large array global

2. Make the large array static:

   static int a[100000][100000];
   

3. Use malloc/calloc and dynamically allocate the large array:

   int **a;
   a=malloc(sizeof(int*)*100000);
   for(int i=0;i<100000;i++)
       a[i]=malloc(sizeof(int)*100000);
   
   /*Use the array*/
   
   for(int i=0;i<100000;i++)
       free(a[i]);
   free(a);
   

来源：https://stackoverflow.com/questions/29444371/dealing-with-large-arrays-without-getting-runtime-error