Insert an element in end of a singly Linked List - c

Question

I have been trying to fix this code since morning but could get it done. So, finally i need some help in figuring out the error. The code compiles with no error but when i run it from terminal i get an error saying "segmetation error: 11"
#include <stdio.h>
#include <stdlib.h>
struct Node{
int data;
struct Node *next;
};
struct Node *head;
void Insert(int data);
void Print();
int main()
{
head = NULL; //list is empty
Insert(3);
Insert(5);
Insert(2);
Insert(8);
Print();
return 0;
}
void Insert(int data)
{
struct Node *temp = malloc(sizeof(struct Node));
temp->data = data;
temp->next = NULL;
struct Node *temp1 = head;
while(temp1 != NULL)
{
temp1= temp1->next;
}
temp1->next = temp;
}
void Print()
{
struct Node *temp =head;
while(temp != NULL)
{
temp = temp->next;
printf("%d", temp->data);
}
}

Answer 1

You never set head to anything other than NULL.
(Even if you fix the above) temp1 is guaranteed to be NULL by the time you get to temp1->next = temp;.
P.S. I don't think it's such a great practice to call you variables temp, temp1 etc. From those names it is impossible to tell what their supposed function is.

Answer 2

Usually single linked lists have an inserting operation that inserts data at the beginning of the list. Nevertheless your function insert can look the following way
void Insert( int data )
{
struct Node *temp = malloc(sizeof( struct Node ) );
temp->data = data;
temp->next = NULL;
if ( head == NULL )
{
head = temp;
}
else
{
struct Node *current = head;
while ( current->next != NULL ) current = current->next;
current->next = temp;
}
}
It would be better if you check in the function whether the node was allocated.
Function Print also is wrong. It can look like
void Print( void )
{
for ( struct Node *current = head; current != NULL; current = current->next )
{
printf( "%d ", current->data );
}
}

Answer 3

You are writing
while(temp1 != NULL)
Make it like this
while(temp1->next != NULL)
Here, temp1 points to null at the end of loop, and you are trying to add node after null i.e.
null->next =temp;
which must be throwing error.

Answer 4

struct Node *curr;
void Insert(int data){
struct Node *temp = malloc(sizeof(struct Node));
temp->data = data;
temp->next =NULL;
if(head == NULL)
curr = head = temp;
else
curr = curr->next = temp;
}
void Print(){
struct Node *temp =head;
while(temp != NULL){
printf("%d ", temp->data);
temp=temp->next;
}
}