Printing strings in linked lists - c

Question

So I'm having trouble getting my program to print both the strings I input, or however many you want to put in the list, it always prints out the last string inputted multiple times. I am sorry about all the commented out code, most of it you don't need to read.
#include<stdio.h>
#include<stdlib.h>
struct node{
char *data;
struct node *next;
}*head;
typedef struct node NODE;
// Function prototypes
void append(char myStr[]);
void add( char myStr[] );
//void addafter(char myStr[], int loc);
void insert(char myStr[]);
int delete(char myStr[]);
void display(struct node *r);
int count();
// main function
int main()
{
int i;
struct node *n;
head = NULL;
char myStr[50];
while(1)
{
printf("\nList Operations\n");
printf("===============\n");
printf("1.Insert\n");
printf("2.Display\n");
printf("3.Size\n");
printf("4.Delete\n");
printf("5.Exit\n");
printf("Enter your choice : ");
if(scanf("%d", &i) <= 0)
{
printf("Enter only an Integer\n");
exit(0);
}
else
{
switch(i)
{
case 1:
printf("Enter the name to insert : ");
scanf("%50s", myStr);
insert(myStr);
break;
case 2:
if(head == NULL)
{
printf("List is Empty\n");
}
else
{
printf("Name(s) in the list are : ");
}
display(n);
break;
case 3:
printf("Size of the list is %d\n",count());
break;
case 4:
if(head == NULL)
printf("List is Empty\n");
else
{
printf("Enter the myStrber to delete : ");
scanf("%50s",myStr);
if(delete(myStr))
printf("%s deleted successfully\n",myStr);
else
printf("%s not found in the list\n",myStr);
}
break;
case 5:
return 0;
default:
printf("Invalid option\n");
}
}
}
return 0;
}
// Function definitions
void append(char myStr[])
{
struct node *temp,*right;
temp = (struct node *)malloc(sizeof(struct node));
temp->data = myStr;
right=(struct node *)head;
while(right->next != NULL)
{
right = right->next;
}
right->next = temp;
right = temp;
right->next = NULL;
}
// adding a node to the beginning of the linked list
void add( char myStr[] )
{
struct node *temp;
temp =(struct node *)malloc(sizeof(struct node));
temp->data = myStr;
// only one node on the linked list
if (head == NULL)
{
head = temp;
head->next = NULL;
}
else
{
temp->next = head;
head = temp;
}
}
void insert(char myStr[])
{
int c = 0;
struct node *temp;
temp = head;
if(temp == NULL)
{
add(myStr);
}
else
{
append(myStr);
}
}
int delete(char myStr[])
{
struct node *temp, *prev;
temp = head;
while(temp != NULL)
{
if(temp->data == myStr)
{
if(temp == head)
{
head = temp->next;
head = (*temp).next;
free(temp);
return 1;
}
else
{
prev->next = temp->next;
free(temp);
return 1;
}
}
else
{
prev = temp;
temp = temp->next;
}
}
return 0;
}
void display(struct node *r)
{
r = head;
if(r == NULL)
{
return;
}
while(r != NULL)
{
printf("%s ", r->data);
r = r->next;
if(r == NULL)
{
printf("\nOur linked list is finished!");
}
}
printf("\n");
}
int count()
{
struct node *n;
int c = 0;
n = head;
while(n != NULL)
{
n = n->next;
c++;
}
return c;
}

Answer 1

The problem seems to be that myStr at main function is a char[], so it's content is overritten every time you insert data. Notice that struct node data field is a char*, it's just pointing to myStr address.
Hope this help!

Answer 2

Your program has only one place to write your input, myStr.
With each input, myStr is erased and a something else is written to myStr.
The data member of all of the nodes, points to myStr. myStr will only contain the last input.
The display() function asks each node what is data. data points to myStr so each node prints the contents of myStr. myStr will only contain the last input so all the nodes print the last input.
To fix this, in the add() and append() functions, you need to give the data member some memory by using malloc(). Then copy the contents of myStr to the data member by using strcpy().
temp->data = malloc ( strlen ( myStr) + 1);
strcpy ( temp->data, myStr);
Do this instead of temp->data = myStr;
You will need #include<string.h>
The memory will need to be free()'d in the delete() function.
free(temp->data);
Do this before freeing temp

Answer 3

char *data
that variable from struct is always assigned with the address of myStr as its a pointer it would only show you the value of myStr