C内存分配问题

Question

I have an algorithm in c in which memory is allocated using malloc many times. I wanted to write a function that would free that memory when the program is all finished but I am unsure how to structure it. Would it just be multiple calls to free() ? I am rather new to C and memory allocation so any help would be greatly appreciated.

Program:

typedef struct State State;
typedef struct Suffix Suffix;

struct State {  /* prefix + suffix list */
    char*   pref[NPREF];    /* prefix words */
    Suffix* suf;            /* list of suffixes */
    State*  next;           /* next in hash table */
};

struct Suffix { /* list of suffixes */
    char *  word;           /* suffix */
    Suffix* next;           /* next in list of suffixes */
};

Answer 1

Every call to malloc should have a corresponding call to free , using the value of the pointer that was returned by malloc .

You'll need to store the values returned by malloc in your program using some sort of container, such as an array, a linked list, and call free on those values before returning from main .

Write a function along the lines of:

void freeMemory()
{
   int i = 0;
   State* sp = NULL;
   State* tmp = NULL;

   for ( i = 0; i < NHASH; ++i )
   {
      sp = statetab[i];
      while ( sp != NULL )
      {
         tmp = sp->next;
         free(sp);
         sp = tmp;
      }
   }
}

and call it from main before the return statement.