I need to merge K ordered lists in O(n*logk). I am trying to create an array of lists and I don't know how to call certain functions (like min_heapify).
void min_heapify(List *list[],int size);
void main() {
List list[10]; // initialize all 10 list randomly in ascending order.
min_heapify(&list,10); // This line won't compile.
}
Please help.
You are passing a pointer to an array, rather than passing an array of pointers expected by your function.
Your function expects an array of list pointers, because it has both an asterisk and a pair of brackets:
List *list[] // <<== This means "an array of pointers to elements of type List"
To pass this function an array of pointers, declare an array of pointers in the main, and make the call:
void main() {
List *list[10];
// intitialize all 10 list pointers randomly in ascending order.
for (int i = 0 ; i != 10 ; i++) {
list[i] = malloc(...); // Initialize list at position i
}
min_heapify(list,10); // Remove the ampersand
}
If you were looking to pass an array of lists, keep only the asterisk or the square brackets:
void min_heapify(List list[],int size);
or the equivalent
void min_heapify(List *list,int size);
Remove the ampersand from the call in the main to compile this properly:
void main() {
List list[10]; // intitialize all 10 lists randomly in ascending order.
min_heapify(list,10); // Remove the ampersand
}
typedef struct LIST{ NODE *first; NODE *last; }LIST; void main(){ int result[10*LISTE],size=10; LIST* list[LISTE]; int i=0,j=0; for(i=0;i<LISTE;i++){ int vect[MAX]; FillRandomArray(vect,size,10,20000,false,1); list[i]->first=NULL; list[i]->last=NULL; }} And I get an error when i try to modify list[i]->first. Why? How should I do this?
list[] is an array of uninitialized pointers. Before you could access list[i]->... you need to allocate memory for the element - say, list[i] = malloc(sizeof(LIST)); Of course you need to free each element once your program ends.Try allocating the array dynamically.
List *list;
list=malloc(sizeof(List)*10);
min_heapify(&list,10);
free(list); //when you don't need list anymore
This will work because
void min_heapify(List *list[],int size);
decays to
void min_heapify(List **list,int size);
