Ниже приведен следующий код, где у меня есть несколько манипуляций со связанным списком.Единственная функция, на которой я фокусируюсь - это searchFast().Перед тем, как скомпилировать код, я получаю предупреждение о том, что «нет возврата в функции, возвращающей non-void [-Wreturn-type].» *
Я думал о том, что я добавляю return NULL.Но это не так.
См. Код ниже:
#include <iostream>
#include <stdio.h>
using namespace std;
struct Node{ //if you want to convert to class, you need to assign access specifiers to public since they're private on default
int data;
struct Node *next;
}*first = NULL;
void create(int A[], int n)
{
struct Node *t; //create a temporary pointer t
struct Node *last; //pointer, points to the last node - helps me add a new node at the END of a linked list
//as of now, the linked list is empty, so we must create the first node!
first = new Node;//create new node on the heap, and first will be pointing on that new node
first -> data = A[0]; // Assign first the first element on the array
first -> next = NULL;//Should point to a null value as it is the only element on the list to start/currently
last = first; //last points on first node
for (int i = 1; i <n; i++)// i starts at element 1 since first has been assigned the 1st element in the array
{
t = new Node; //create a new node
t->data = A[i]; //fill up the data of t from A[i] which will be iterated through and assigned to data
t->next = NULL; // the next node should be pointing to NULL, as there is nothing at the moment when the iteration begins that it is initially pointing to
last -> next = t;
last = t;
}
}
Node * searchFast( struct Node * p, int key){
Node * q = NULL;
while (p != NULL){
if(key == p->data){
q->next = p->next;
p->next = first;
first = p;
return p;
}
q = p;
p = p->next;
}
return NULL;
}
void display (struct Node *p)
{
while (p != 0 )
{
cout<<p->data<<" ";
cout<<p->next<<" ";
p = p->next;
}
}
int main() {
int A [] = {1,2,3,18,5, 6, 7};
create (A,7);
display(first);
cout<<"If following value 18 can be found in the linked list, its address is the following: "<<searchFast(first, 18);
return 0;
}