Question

I am trying to make “Hello World” to “World Hello”.
But the code is not working properly the way I wanted it to behave.
See the code below:

#include<stdio.h>
#include<string.h>
#include<stdlib.h>
struct llnode
{
    char *info;
    struct llnode *next;
};

typedef struct llnode NODE;

int main()
{
    char msg[50],word[10],*str;
    int i=0,length=0,j=0;
    NODE *ptr,*front=NULL,*temp,*last=NULL;

    //printf("Enter the sentence: ");
    str= "Hello World"; //fgets(msg,sizeof(msg),stdin);

    while(str[i]!='\0')
    {
        if((str[i]==' ')||(str[i]=='\n'))
        {
            word[j]='\0';
            j=0;
            ptr=(NODE *)malloc(sizeof(NODE));
            ptr->info=word;
            ptr->next=NULL;

            if(front==NULL)
            {
                front=ptr; // only change the value of front here;
            }
            else
            {
                temp=front;
                while((temp->next)!=NULL)
                {
                    temp=temp->next;
                }
                temp->next=ptr;
            }
            printf("\n##%s\n",front->info); // prints thewords and not
            //the first word
        }
        else
        {
            word[j]=str[i];
            j++;
        }
        i++;
    }

    temp=front;
    while(temp)
    {
        length++;
        printf("%s ",temp->info);
        temp=temp->next;
    }
    printf("\nLength of Linked List(or, number of words): %d\n",length);

    i=0;
    printf("\n************************\n");

    while(i<length)
    {
        temp=front;
        while(temp->next!=last)
        {
            temp=temp->next;
        }
        last=temp;
        printf("%s ",temp->info);
    i++;
}

return 0;
}

Thanks

Answer 1

There are a number of things wrong with the code:

You are using a single word array to read all the words. So, when you read “Hello”, you read into the word array, print “##Hello” and store the pointer to the word array as front->info. Then, you OVERWRITE the word array with World. Also, please note that you NEVER add a node with the word “World” because you exit the loop as soon as you encounter the ‘\0’. So, your linked list contains only one node. But, there is a problem, since you stored a pointer to the word array in the first node and since the word array has been overwritten with “World”, when you exit the loop, there is only one node in the list and the info of this node is word array which contains “World” and not “Hello” like it once did. So, I guess this explains the output?