remove duplicate words from linked list

This is a discussion on remove duplicate words from linked list within the C Programming forums, part of the General Programming Boards category; how do i locate and delete duplicate words ?? my search function doesnt seem to work; Code: p = (Node ...

  1. #1
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    Unhappy remove duplicate words from linked list

    how do i locate and delete duplicate words ??
    my search function doesnt seem to work;

    Code:
    p = (Node *) malloc(sizeof(Node));
    	strcpy(p->word,word);
    	p->next = head;
    	head = p;
    search(word,p);
    Code:
    int search(char* check,Node *p) 
    {
    while( p!= NULL ) 
    {
        if(p->word == check)
        printf("Found!");
    	p = p->next;
    }
    }

  2. #2
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    So how often do you think that the address you are looking for is at the same address in memory as the one in the list? Because that is what you are comparing.

    Perhaps you meant to use strcmp() but forgot?

    --
    Mats
    Compilers can produce warnings - make the compiler programmers happy: Use them!
    Please don't PM me for help - and no, I don't do help over instant messengers.

  3. #3
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    oops!..yep thats what i meant
    if(strcmp(p->word, check)==0)
    printf(found);

    but now it returns found after i type in any word..where should i put the search function so that it only looks for duplicates and not when the word is entered the first time ???

  4. #4
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    Perhaps you need to post some more of your code?

    --
    Mats
    Compilers can produce warnings - make the compiler programmers happy: Use them!
    Please don't PM me for help - and no, I don't do help over instant messengers.

  5. #5
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    Code:
    p = (Node *) malloc(sizeof(Node));
    	strcpy(p->word,word);
    	p->next = head;
    	head = p;
           search(word,p);
    Last edited by rocketman03; 11-22-2008 at 07:25 PM.

  6. #6
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    If you insert a word in the list, do you expect to find it?

    Because that's exactly what you do:
    Code:
    	p = (Node *) malloc(sizeof(Node));
    	strcpy(p->word,word);
    	p->next = head;
    	head = p;
           search(word,p);
    The first four lines in that code inserts the string into the first position of the list, then searches the list for that word.

    Perhaps doing it the other way around would work better?

    You also shouldn't cast the return value from malloc() - if the compiler complains about that, it's probably because you are compiling your code as C++, not C (or you forgot to include stdlib.h or similar).

    --
    Mats
    Compilers can produce warnings - make the compiler programmers happy: Use them!
    Please don't PM me for help - and no, I don't do help over instant messengers.

  7. #7
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    well..if i put it before i ask for the word then it just crashes the program , and the same thing happens if i dont the cast the value from malloc ?..is there another way to remove duplicate words ?

  8. #8
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    Well, is that exactly just moving search() up to before the inserting of the word into the list? If so, I expect that it will do that - because it uses p that isn't initialized, rather than head which IS initialized to NULL, so we know that the list is empty, rather than p having some random value that is PROBABLY not a good pointer to a Node structure, and thus leads to undefined behaviour (which is usually a crash, but not guaranteed).

    --
    Mats
    Compilers can produce warnings - make the compiler programmers happy: Use them!
    Please don't PM me for help - and no, I don't do help over instant messengers.

  9. #9
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    oh yeaa! i know what you mean! thank you!!
    Last edited by rocketman03; 11-22-2008 at 06:49 PM.

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