Help With Bubble Sort

This is a discussion on Help With Bubble Sort within the C Programming forums, part of the General Programming Boards category; Okay, I'm back again. From what I understand this bubble sort, should sort the entire struct in ascending order according ...

  1. #1
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    Help With Bubble Sort

    Okay, I'm back again. From what I understand this bubble sort, should sort the entire struct in ascending order according to the price member... But it just prints out the struct in its original form for me. Probably just a stupid mistake, but can anyone point it out?

    Code:
    #include <stdio.h>
    #include <conio.h>
    
    #define NUM 5
    
    struct inv {
        char partID[6];
        int quantity;
        float price;
    };
    
    void invSort(struct inv items[NUM]);
    void invPrint(struct inv items[NUM]);
    
    main() 
    {
        struct inv items[NUM] = {{"HDWR9", 13, 4.53},
                                 {"WDGT4", 2, 15.82},
                                 {"POPL0", 4, 8.32},
                                 {"RTYN6", 7, 5.40},
                                 {"LOUN4", 61, 7.43}};
         
        printf("Inventory\n\n");
        invSort(items);
        invPrint(items);
         
        printf("\n\nPress any key to continue...");
        getch();
        return 0;
    } 
    
    void invSort(struct inv items[NUM])
    {
        int inner, outer;
        struct inv temp;
        int didSwap;
        
        for (outer = 0; outer < (NUM - 1); outer++) {
        didSwap = 0;
            for (inner = outer; inner < NUM; inner++) {
                if (items[outer].price > items[inner].price) {
                temp = items[outer];
                items[outer] = items[inner];
                items[inner] = temp;
                didSwap = 1;
                }
            }
            if (!didSwap) {
            break;
            }
        }
        return;
    }
    
    void invPrint(struct inv items[NUM]) 
    {
        int ctr = 0;
        
        for (ctr = 0; ctr < NUM; ctr++) {
        printf("Part ID: %s, Quantity: %d, Price: $%6.2f\n",
        items[ctr].partID, items[ctr].quantity, items[ctr].price);
        }
        return;
    }

  2. #2
    Code Goddess Prelude's Avatar
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    Compare and contrast:
    Code:
    void invSort(struct inv items[NUM])
    {
      int inner, outer;
      struct inv temp;
      int didSwap;
    
      for (outer = NUM - 1; outer > 0; outer--) {
        didSwap = 0;
        for (inner = 0; inner < outer; inner++) {
          if (items[inner].price > items[inner + 1].price) {
            temp = items[inner];
            items[inner] = items[inner + 1];
            items[inner + 1] = temp;
            didSwap = 1;
          }
        }
        if (!didSwap) {
          break;
        }
      }
      return;
    }
    Write down the execution of both your version and mine to see how they work. Nothing beats manual tracing like that for understanding an algorithm.
    My best code is written with the delete key.

  3. #3
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    Gah, this book is upsetting me. That code is almost exact, word for word from the book. I don't understand why it would be wrong!

  4. #4
    ATH0 quzah's Avatar
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    That code is almost exact, word for word from the book. I don't understand why it would be wrong!
    This isn't by any chance a book by Herbert Schildt would it?

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

  5. #5
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    Umm, nope, it's this one...
    http://www.amazon.com/exec/obidos/tg...glance&s=books

    I also have this one, but it's quite complex so I'm learning all the basics before i dive into it:
    http://www.amazon.com/exec/obidos/tg...glance&s=books
    Last edited by Explicit; 05-27-2004 at 01:38 PM.

  6. #6
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    Hmm this works aswell:

    Code:
    void invSort(struct inv items[NUM])
    {
        int inner, outer;
        struct inv temp;
        int didSwap;
        
        for (outer = (NUM -1); outer >= 0; outer--) {
        didSwap = 0;
            for (inner = 1; inner <= outer; inner++) {
                if (items[inner - 1].price > items[inner].price) {
                temp = items[inner - 1];
                items[inner - 1] = items[inner];
                items[inner] = temp;
                didSwap = 1;
                }
            }
            if (!didSwap) {
            break;
            }
        }
        return;
    }

  7. #7
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    books!

    Quote Originally Posted by Explicit
    Umm, nope, it's this one...
    http://www.amazon.com/exec/obidos/tg...glance&s=books

    I also have this one, but it's quite complex so I'm learning all the basics before i dive into it:
    http://www.amazon.com/exec/obidos/tg...glance&s=books
    Buy Schaums outlines series especially B.S.Gottfried's "Programming with C". It is decent for beginners. Then you can move to K&R, the bible of C

  8. #8
    Code Goddess Prelude's Avatar
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    >It is decent for beginners.
    Decent for the price, but I wouldn't recommend it over better beginner's texts such as "Pointers on C" by Kenneth Reek.
    My best code is written with the delete key.

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