Sorting within a stucture

This is a discussion on Sorting within a stucture within the C Programming forums, part of the General Programming Boards category; Code: struct stud{ char name[30]; int grade[4]; float avg; } Then in the program i do this: Code: struct stud ...

  1. #1
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    Sorting within a stucture

    Code:
    struct stud{
    
              char name[30];
              int grade[4];
              float avg;
    
    }
    Then in the program i do this:

    Code:
    struct stud students[];
    
    ..
    ..
    Then I need a function which will sort the grades for each student from lowest to highest..
    N is the number of students
    Code:
    void sort(stuct student[], int n){
    
            int i, j, lowest, highest, temp;
    
            for(i=0;i<n;i++)
                 for(j=0;j<4;j++){
                      lowest=student[i].grade[j];
                      highest=student[i].grade[j+1];
    
                      if(lowest>highest){
                     
                         temp=student[i].grade[j];
                         student[i].grade[j]=student[i].grade[j+1];
                         student[i].grade[j+1]=temp;
                 
                        }
                 }
    will this work ??
    any help?

    all I want to know is how to sort the 4 grades within the structure for each student.
    Last edited by Zeff; 11-28-2006 at 03:48 PM.

  2. #2
    Devil's Advocate SlyMaelstrom's Avatar
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    Here you go... look at these: http://eternallyconfuzzled.com/tuts/sorting.html

    Specifically Bubble Sort or Selection Sort as those will probably be the easiest for you to understand conceptually. You're going to want to use one of those to sort the grades, and then you're going to need another loop around your sort to go through each student.
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  3. #3
    and the hat of int overfl Salem's Avatar
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    Well if you make your temp to be
    struct stud temp;

    And swap the whole structure, then you could be onto something.
    If you dance barefoot on the broken glass of undefined behaviour, you've got to expect the occasional cut.
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    {Jaxom,Imriel,Liam}'s Dad Kennedy's Avatar
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    Except that the OP is attempting to sort an array within the struct. . . The OP appears to be sorting the grades of each student, not the students themselves.

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    Yeah, I do not want to sort the student themselves(yet), just the 4 grades within each student

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    I was also working it like this:

    Code:
    for(i=0;i<n;i++) // going through each student
    
        for(j=0;j<4;j++) // going through each grade within the structure (4 grades)
    
           for(k=j+1;k<5,k++) // checking each grade to all the other grades
    
              if(students[i].grade[j]>students[i].grade[k]){
                 temp=students[i].grade[j];
                 students[i].grade[j]=students[i].grade[k];
                 students[i].grade[k]= temp;
                }

  7. #7
    Devil's Advocate SlyMaelstrom's Avatar
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    Quote Originally Posted by Salem
    Well if you make your temp to be
    struct stud temp;

    And swap the whole structure, then you could be onto something.
    Hehe... I said the same thing at first but then deleted my post. I misunderstood what he wanted to sort because I didn't bother reading the last line.
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    Quote Originally Posted by Zeff
    I was also working it like this:

    Code:
    for(i=0;i<n;i++) // going through each student
    
        for(j=0;j<4;j++) // going through each grade within the structure (4 grades)
    
           for(k=j+1;k<5,k++) // checking each grade to all the other grades
    
              if(students[i].grade[j]>students[i].grade[k]){
                 temp=students[i].grade[j];
                 students[i].grade[j]=students[i].grade[k];
                 students[i].grade[k]= temp;
                }
    Is this any good ?

    I'm pretty sure it will work, but I think that there is an easier way.

    What do you guys think?

  9. #9
    Registered User ssharish2005's Avatar
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    well there different ways of sorting. But that above sorting method looks ok.

    ssharish2005

  10. #10
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    Thanks.

  11. #11
    CSharpener vart's Avatar
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    I prefer to build functions for such purposes... You trying to sort an array - so sort function need not to know that the array is a memeber of some struct or not

    I think using such function makes code more readable - both inside the sort loop, and outside - where we scanning all students...
    I mean smthing like
    Code:
    sortGrades(int grades[], int size);
    
    for(i=0;i<n;i++) 
    {
       sortGrades(students[i].grade,4);
    }
    Last edited by vart; 11-28-2006 at 11:58 PM.
    The first 90% of a project takes 90% of the time,
    the last 10% takes the other 90% of the time.

  12. #12
    CSharpener vart's Avatar
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    PS. k<5 - goes out of bounds of the array
    The first 90% of a project takes 90% of the time,
    the last 10% takes the other 90% of the time.

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