C linked list search function

Question

Edit: Stupid error. I found it. Thanks for the help though.

Sorry i can't keep my code up

Answer 1

As suggested in the comments, you're dereferencing freqTable in elementExists before any nodes are allocated. Thus, freqTable is always NULL, so you invoke undefined behavior. You could just add a check for NULL in elementExists, and return false in that case.

Answer 2

In the function elementExists you need to ensure that freqTable is not NULL :

bool elementExists(int n){
 if(freqTable) {  // add this check
   printf("%d\n", freqTable->number);
 }
}

Also your elementExists does not do what its supposed to do(check for existence of a node with value n), you should do something like:

bool elementExists(int n) {

 if(!freqTale) { // table does not exist..return false.
  return false;
 }
 // table exists..iterate node by node and check.
 struct node *tmp = freqTable;
 while(tmp) { // loop till tmp becomes NULL
  if(*tmp == n) { // it node contains n..return false.
    return true;
   }
  tmp = tmp->next; // move on
 }
 return false; // n does not exist in the list..return false.
}

Answer 3

There's a problem with the call to elementExists:

if(elementExists(&freqTable, newNum)){

You pass the address of freqTable (i.e. a pointer to where the pointer to the first element of the list is stored) instead of its value. Yet in elementExists you dereference the argument as though it were a pointer to a list element:

printf("Compare with: %d\n", list->number);

and

else list = list->next;

Remove the & from the call to elementExists. And don't reference the global freqTable inside elementExists if you are passing the list as an argument.