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help with question from exam in c...

This is a discussion on help with question from exam in c... within the C Programming forums, part of the General Programming Boards category; Given the following definition: Code: typedef struct node node;struct node{ char* str; node* next; }; And this function: Code: void ...

  1. #1
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    help with question from exam in c...

    Given the following definition:

    Code:
    typedef struct node node;struct node{ 
     char* str; 
     node* next; 
    };
    And this function:

    Code:
    void what(node* x){  node *temp, *y; 
     
     if (!x) 
      return; 
     
     y = x->next; 
     while (y && x->str[strlen(x->str)-1] != y->str[0]) { 
      temp = y; 
      x->next = temp->next; 
      free(temp); 
      y = x->next; 
     } 
     
     what(y); 
    }
    The List is:
    Hello -> open -> all -> leave -> never -> radio -> table

    1. What the new list after call to what(list)?
    2. What is the function purpose is what?

    Thanks!

  2. #2
    Programming Wraith GReaper's Avatar
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    Let's have a look at that code here:

    Code:
    void what(node* x)
    {
        node *temp, *y;
    
        if (!x) /* if x == NULL, return */
            return;
      
        y = x->next; /* y refers to the node next to x */
        while (y && x->str[strlen(x->str)-1] != y->str[0]) /* While y != NULL and x's last char != y's first char */
        {
            temp = y;
            x->next = temp->next; /* Move the list backwards */
            free(temp);   /* Free the detached node */
            y = x->next;
        }
    
        what(y); /* Will be recursively called until y == NULL */
    }
    Isn't it obvious now?
    stahta01 likes this.
    Devoted my life to programming...

  3. #3
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    This comment confuses me.
    Code:
    x->next = temp->next; /* Move the list backwards */
    I would do this; does it makes sense to you?
    Code:
    x->next = temp->next; /* Remove temp from the list */
    Tim S.
    "Programming today is a race between software engineers striving to build bigger and better idiot-proof programs, and the universe trying to produce bigger and better idiots. So far, the Universe is winning." Rick Cook

  4. #4
    Programming Wraith GReaper's Avatar
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    Quote Originally Posted by stahta01 View Post
    I would do this; does it makes sense to you?
    Code:
    x->next = temp->next; /* Remove temp from the list */
    Yeah, that's what I meant, I don't know why I wrote it the way I did.
    Devoted my life to programming...

  5. #5
    ATH0 quzah's Avatar
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    Quote Originally Posted by GReaper View Post
    Let's have a look at that code here:
    ...
    Isn't it obvious now?
    There's nothing quite like the feel you get after doing someone's homework for them without any effort on their part, right?


    Quzah.
    Hope is the first step on the road to disappointment.

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    Code:
    y = x->next; /* y refers to the node next to x */
    this is command is not entirely clear.

    in first x equal "hello" right?
    and y after this command equal x->next equal "open"?

    thanks.

  7. #7
    Programming Wraith GReaper's Avatar
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    Quote Originally Posted by quzah View Post
    There's nothing quite like the feel you get after doing someone's homework for them without any effort on their part, right?
    o_O Well, I didn't post anything new, I just explained his code a bit!
    Devoted my life to programming...

  8. #8
    Programming Wraith GReaper's Avatar
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    Quote Originally Posted by engti View Post
    in first x equal "hello" right?
    and y after this command equal x->next equal "open"?
    Change "equal" to "refers to", you'll make your like easier.
    Devoted my life to programming...

  9. #9
    a_capitalist_story
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    Quote Originally Posted by GReaper View Post
    o_O Well, I didn't post anything new, I just explained his code a bit!
    Except that's exactly what he wanted!

    1. What the new list after call to what(list)?
    2. What is the function purpose is what?
    In other words, the overall question was "Figure out the logic of this function". You did that via your comments.

  10. #10
    Programming Wraith GReaper's Avatar
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    Quote Originally Posted by rags_to_riches View Post
    In other words, the overall question was "Figure out the logic of this function". You did that via your comments.
    Well, I didn't draw a flowchart!
    Devoted my life to programming...

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