Question

Write a C program that creates and prints out a linked list of strings.

• Define your link structure so that every node can store a string of up to 255 characters.

• Implement the function insert_dictionary_order that receives a word (of type char*) and inserts is into the right position.

• Implement the print_list function that prints the list.

• In the main function, prompt the user to enter strings (strings are separated by white-spaces, such as space character, tab, or newline).

• Read and insert every string into the link list until you reach a single dot “.” or EOF.

• Print the list. Use scanf to read strings. Use strcpy() for copying strings.

Here is a sample text input:

This is a sample text. The file is terminated by a single dot: .

Answer 1

#include<stdio.h>
#include<string.h>
#include<stdlib.h>
//defining node structure
typedef struct node
{
   char data[255];//can store upto 255 characters
   struct node *next;
}Node;
Node *head=NULL;//initially linked list is empty
//method to insert in sorted order
void insert_dictionary_order(char *a)
{
   Node *n = (Node*)malloc(sizeof(Node));//creating new node
   strcpy(n->data,a);//reading data
   n->next=NULL;
   Node *temp=head,*prev=NULL;
   if(temp==NULL)
   {
       head=n;  
   }
   else
   {//inserting in right position
       while(temp!=NULL)
       {
           if(0<strcmp(temp->data,a))
           break;
           prev=temp;
           temp=temp->next;  
       }
       if(prev==NULL)
       {
           n->next=head;
           head=n;  
       }
       else
       {
           n->next=prev->next;
           prev->next=n;  
       }  
   }
}
//method to print all words in list
void print_list()
{
   Node *temp=head;
   while(temp!=NULL)
   {
       printf("%s ",temp->data);
       temp=temp->next;  
   }
   printf("\n");
}
int main()
{
   printf("Enter words seperated by spaces:(. or EOF to stop):\n");
  
   do
   {
       char s[255];
       scanf("%s",s);
       if(strcmp(s,".")==0 || strcmp(s,"EOF")==0)
       {
           insert_dictionary_order(s);//adding to list
           break;
       }
       else
       {
           insert_dictionary_order(s);//adding to list  
       }
   }
   while(1);
   //now printing list
   print_list();
   return 0;
}

output:

Enter words seperated by spaces:(. or EOF to stop):
This is a sample text. The file is terminated by a single dot: .
. The This a a by dot: file is is sample single terminated text.

Process exited normally.
Press any key to continue . . .