I'm learning double linked list and trying to code it. I encountered an error and I couldn't fix it after searching for 5 hours.
my code is
#include <stdio.h>
#include <curses.h>
#include <stdlib.h>
struct node
{
struct node *next;
int data;
struct node *prev;
};
struct node *start = NULL;
struct node *create_ll(struct node *);
struct node *display(struct node *);
struct node *insert_beg(struct node *);
struct node *insert_end(struct node *);
struct node *insert_before(struct node *);
struct node *insert_after(struct node *);
struct node *delete_beg(struct node *);
struct node *delete_end(struct node *);
struct node *delete_before(struct node *);
struct node *delete_after(struct node *);
struct node *delete_list(struct node *);
int main()
{
int option;
do
{
printf("\n\n *****MAIN MENU *****");
printf("\n 1: Create a list");
printf("\n 2: Display the list");
printf("\n 3: Add a node at the beginning");
printf("\n 4: Add a node at the end");
printf("\n 5: Add a node before a given node");
printf("\n 6: Add a node after a given node");
printf("\n 7: Delete a node from the beginning");
printf("\n 8: Delete a node from the end");
printf("\n 9: Delete a node before a given node");
printf("\n 10: Delete a node after a given node");
printf("\n 11: Delete the entire list");
printf("\n 12: EXIT");
printf("\n\n Enter your option : ");
scanf("%d", &option);
switch(option)
{
case 1: start = create_ll(start);
printf("\n DOUBLY LINKED LIST CREATED");
break;
case 2: start = display(start);
break;
case 3: start = insert_beg(start);
break;
case 4: start = insert_end(start);
break;
case 5: start = insert_before(start);
break;
case 6: start = insert_after(start);
break;
case 7: start = delete_beg(start);
break;
case 8: start = delete_end(start);
break;
case 9: start = delete_before(start);
break;
case 10: start = delete_after(start);
break;
case 11: start = delete_list(start);
printf("\n DOUBLY LINKED LIST DELETED");
break;
}
}while(option != 12);
getch();
return 0;
}
struct node *create_ll(struct node *start)
{
struct node *new_node, *ptr;
int num;
printf("\n Enter –1 to end");
printf("\n Enter the data : ");
scanf("%d", &num);
while(num != -1)
{
if(start == NULL)
{
new_node = (struct node*)malloc(sizeof(struct node));
new_node -> prev = NULL;
new_node -> data = num;
new_node -> next = NULL;
start = new_node;
}
else
{
ptr=start;
new_node = (struct node*)malloc(sizeof(struct node));
new_node->data=num;
while(ptr->next!=NULL)
ptr = ptr->next;
ptr->next = new_node;
new_node->prev=ptr;
new_node->next=NULL;
}
printf("\n Enter the data : ");
scanf("%d", &num);
}
return start;
}
struct node *display(struct node *start)
{
struct node *ptr;
ptr=start;
while(ptr!=NULL)
{
printf("\t %d", ptr -> data);
ptr = ptr -> next;
}
return start;
}
struct node *insert_beg(struct node *start)
{
struct node *new_node;
int num;
printf("\n Enter the data : ");
scanf("%d", &num);
new_node = (struct node *)malloc(sizeof(struct node));
new_node -> data = num;
start -> prev = new_node;
new_node -> next = start;
new_node -> prev = NULL;
start = new_node;
return start;
}
struct node *insert_end(struct node *start)
{
struct node *ptr, *new_node;
int num;
printf("\n Enter the data : ");
scanf("%d", &num);
new_node = (struct node *)malloc(sizeof(struct node));
new_node -> data = num;
ptr=start;
while(ptr -> next != NULL)
ptr = ptr -> next;
ptr -> next = new_node;
new_node -> prev = ptr;
new_node -> next = NULL;
return start;
}
struct node *insert_before(struct node *start)
{
struct node *new_node, *ptr;
int num, val;
printf("\n Enter the data : ");
scanf("%d", &num);
printf("\n Enter the value before which the data has to be inserted : ");
scanf("%d", &val);
new_node = (struct node *)malloc(sizeof(struct node));
new_node -> data = num;
ptr = start;
while(ptr -> data != val)
ptr = ptr -> next;
new_node -> next = ptr;
new_node -> prev = ptr-> prev;
ptr -> prev -> next = new_node;
ptr -> prev = new_node;
return start;
}
struct node *insert_after(struct node *start)
{
struct node *new_node, *ptr;
int num, val;
printf("\n Enter the data : ");
scanf("%d", &num);
printf("\n Enter the value after which the data has to be inserted : ");
scanf("%d", &val);
new_node = (struct node *)malloc(sizeof(struct node));
new_node -> data = num;
ptr = start;
while(ptr -> data != val)
ptr = ptr -> next;
new_node -> prev = ptr;
new_node -> next = ptr -> next;
ptr -> next -> prev = new_node;
ptr -> next = new_node;
return start;
}
struct node *delete_beg(struct node *start)
{
struct node *ptr;
ptr = start;
start = start -> next;
start -> prev = NULL;
free(ptr);
return start;
}
struct node *delete_end(struct node *start)
{
struct node *ptr;
ptr = start;
while(ptr -> next != NULL)
ptr = ptr -> next;
ptr -> prev -> next = NULL;
free(ptr);
return start;
}
struct node *delete_after(struct node *start)
{
struct node *ptr, *temp;
int val;
printf("\n Enter the value after which the node has to deleted : ");
scanf("%d", &val);
ptr = start;
while(ptr -> data != val)
ptr = ptr -> next;
temp = ptr -> next;
ptr -> next = temp -> next;
temp -> next -> prev = ptr;
free(temp);
return start;
}
struct node *delete_before(struct node *start)
{
struct node *ptr, *temp;
int val;
printf("\n Enter the value before which the node has to deleted : ");
scanf("%d", &val);
ptr = start;
while(ptr -> data != val)
ptr = ptr -> next;
temp = ptr -> prev;
if(temp == start)
start = delete_beg(start);
else
{
ptr -> prev = temp -> prev;
temp -> prev -> next = ptr;
}
free(temp);
return start;
}
struct node *delete_list(struct node *start)
{
while(start != NULL)
start = delete_beg(start);
return start;
}
and my terminal says..
cd "/Users/andysohn/Desktop/Suits/" && gcc tempCodeRunnerFile.c -o tempCodeRunnerFile && "/Users/andysohn/Desktop/Suits/"tempCodeRunnerFile andysohn@Andyui-MacBookPro Suits % cd "/Users/andysohn/Desktop/Suits/" && gcc tempCodeRunnerFile.c -o tempCodeRunnerFile && "/Users/andysohn/Desktop/Suits/"tempCodeRunnerFile Undefined symbols for architecture x86_64: "_stdscr", referenced from: _main in tempCodeRunnerFile-7f7d00.o "_wgetch", referenced from: _main in tempCodeRunnerFile-7f7d00.o ld: symbol(s) not found for architecture x86_64 clang: error: linker command failed with exit code 1 (use -v to see invocation)
please help me..
