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Polly's suitors in ONE HOUR!

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Join Date: Mar 2007

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Polly's suitors in ONE HOUR!

Mar 26th, 2007

hello!
I badly need to submit this program within an hour from now so any help out there who could help debug my code, i would really appreciate it. there's something wrong with my qsort() syntax but i can't figure out what . spent 5 hours trying every possible ways for it but got no luck.
PLS HELP ME!!!

Here's the code:

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#include <iostream>
#include <fstream>
#include <cstdio>
#include <string>
#include <cstdlib>
#include <math.h>
#include <iomanip>
 
#define DESIRED_HEIGHT 180 //Polly's desired height in cm
#define DESIRED_WEIGHT 75 //Polly's desired weight in kg
 
using namespace std;
 
int compare_suitor();
 
struct suitorData{
    char firstName[30];    //maximum length of suitor's firstname
    char lastName[30]; //maximum length of suitor's lastname         
    int height;            
    int weight;            
};
 
int main(){
    int i; 
    int height=0;
    int weight=0;
    int numberOfSuitors=0;
    char firstName[30];
    char lastName[30];
    ifstream inSuitorFile("suitors.txt", ios::in);
    if(!inSuitorFile){
       cerr<<"File could not be opened!";
       exit(1);
    }
    suitorData suitor[20]; //maximum number of suitors
    while(inSuitorFile>>suitor[numberOfSuitors].firstName>>suitor[numberOfSuitors].lastName>>
          suitor[numberOfSuitors].height>>suitor[numberOfSuitors].weight){
          cout<<lastName<<","<<" "<<firstName <<" "<<height <<" "<<weight <<endl;
          suitor[numberOfSuitors].height = abs(height - DESIRED_HEIGHT);
        if (weight > DESIRED_WEIGHT)
            suitor[numberOfSuitors].weight = weight - DESIRED_WEIGHT;
        else
            suitor[numberOfSuitors].weight = - weight;
 
        numberOfSuitors ++;
    }
    //qsort(reinterpret_cast<char*>(suitor), numberOfSuitors,
              //sizeof(suitorData ), compare_suitor());
    qsort(suitor, numberOfSuitors, sizeof(suitorData), compare_suitor); //either of the two isn't working... what's wrong?!?
 
    for (i=0; i<numberOfSuitors; i++){ 
        cout<<suitor[i].lastName, suitor[i].firstName);
    }
    system("pause");
    return 0;
}
 
int compare_suitor(suitorData *a, suitorData *b)
{   
    int result;            //result of comparsion 
    if (a->height < b->height) 
       return(-1);
    if (a->height > b->height) 
       return(1);
    if (a->weight < b->weight) 
       return(-1);
    if (a->weight > b->weight) 
       return(1);
 
    if ((result=strcmp(a->lastName,b->lastName)) != 0) 
       return result;
 
    return(strcmp(a->firstName,b->firstName));
}
#include <iostream>
#include <fstream>
#include <cstdio>
#include <string>
#include <cstdlib>
#include <math.h>
#include <iomanip>

#define DESIRED_HEIGHT 180 //Polly's desired height in cm
#define DESIRED_WEIGHT 75 //Polly's desired weight in kg

using namespace std;

int compare_suitor();

struct suitorData{
    char firstName[30];    //maximum length of suitor's firstname
    char lastName[30]; //maximum length of suitor's lastname         
    int height;            
    int weight;            
};

int main(){
    int i; 
    int height=0;
    int weight=0;
    int numberOfSuitors=0;
    char firstName[30];
    char lastName[30];
    ifstream inSuitorFile("suitors.txt", ios::in);
    if(!inSuitorFile){
       cerr<<"File could not be opened!";
       exit(1);
    }
    suitorData suitor[20]; //maximum number of suitors
    while(inSuitorFile>>suitor[numberOfSuitors].firstName>>suitor[numberOfSuitors].lastName>>
          suitor[numberOfSuitors].height>>suitor[numberOfSuitors].weight){
          cout<<lastName<<","<<" "<<firstName <<" "<<height <<" "<<weight <<endl;
          suitor[numberOfSuitors].height = abs(height - DESIRED_HEIGHT);
        if (weight > DESIRED_WEIGHT)
            suitor[numberOfSuitors].weight = weight - DESIRED_WEIGHT;
        else
            suitor[numberOfSuitors].weight = - weight;

        numberOfSuitors ++;
    }
    //qsort(reinterpret_cast<char*>(suitor), numberOfSuitors,
              //sizeof(suitorData ), compare_suitor());
    qsort(suitor, numberOfSuitors, sizeof(suitorData), compare_suitor); //either of the two isn't working... what's wrong?!?

    for (i=0; i<numberOfSuitors; i++){ 
        cout<<suitor[i].lastName, suitor[i].firstName);
    }
    system("pause");
    return 0;
}

int compare_suitor(suitorData *a, suitorData *b)
{   
    int result;            //result of comparsion 
    if (a->height < b->height) 
       return(-1);
    if (a->height > b->height) 
       return(1);
    if (a->weight < b->weight) 
       return(-1);
    if (a->weight > b->weight) 
       return(1);

    if ((result=strcmp(a->lastName,b->lastName)) != 0) 
       return result;

    return(strcmp(a->firstName,b->firstName));
}

ps. you need to create a file 'suitors.txt' for it to work. (data firstnames, surnames, height and weight)

thanks!

Last edited by sakura_fujin; Mar 26th, 2007 at 11:35 am.

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vijayan121 vijayan121 is offline

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Re: Polly's suitors in ONE HOUR!

Mar 26th, 2007

the compare function should have this signature:
[inliecode]
int (*)(const void*, const void*)
[/inlinecode]
a. declare the function with the right signature.
b. in the definition, cast the args to const suitorData*, then compare.

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Re: Polly's suitors in ONE HOUR!

Mar 26th, 2007

why use qsort() ? use the c++ sort() that's in algorithm header file. I don't know if qsort() works with vectors.

Don't PM me with questions -- you might get a nasty PM in response. If you have a question then post it in one of the forums.

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Re: Polly's suitors in ONE HOUR!

Mar 26th, 2007

qsort would work with std::vector (if the elements are POD).
qsort( &vec.begin(), ...

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Re: Polly's suitors in ONE HOUR!

Mar 26th, 2007

still doesn't work....

whenever i follow the right syntax, errors are multiplying itself...

our prof requires us to use qsort()

i tried something new and my only error now is linker error what does that mean???

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Ancient Dragon Ancient Dragon is offline

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Re: Polly's suitors in ONE HOUR!

Mar 26th, 2007

what is the link error?

Don't PM me with questions -- you might get a nasty PM in response. If you have a question then post it in one of the forums.

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Re: Polly's suitors in ONE HOUR!

Mar 26th, 2007

[Linker error] undefined reference to `compare_suitor(void const*, void const*)'
ld returned 1 exit status

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Re: Polly's suitors in ONE HOUR!

Mar 26th, 2007

modify the function from

 Help with Code Tags 
 C++ Syntax (Toggle Plain Text) 
int compare_suitor(suitorData *a, suitorData *b)
{   
    int result;            //result of comparsion 
    if (a->height < b->height) 
    // ...
[FONT=verdana,geneva,lucida,'lucida grande',arial,helvetica,sans-serif]
int compare_suitor(suitorData *a, suitorData *b)
{   
    int result;            //result of comparsion 
    if (a->height < b->height) 
    // ...
[FONT=verdana,geneva,lucida,'lucida grande',arial,helvetica,sans-serif]

 Help with Code Tags 
 C++ Syntax (Toggle Plain Text) 
int compare_suitor(const void*aa, const void* bb)
{   
   const suitorData* a = static_cast<const 
suitorData*>(aa) ;
   const suitorData* b = static_cast<const 
suitorData*>(bb) ;
    int result;            //result of comparsion 
    if (a->height < b->height) 
    // ...
[FONT=verdana,geneva,lucida,'lucida grande',arial,helvetica,sans-serif]
int compare_suitor(const void*aa, const void* bb)
{   
   const suitorData* a = static_cast<const 
suitorData*>(aa) ;
   const suitorData* b = static_cast<const 
suitorData*>(bb) ;
    int result;            //result of comparsion 
    if (a->height < b->height) 
    // ...
[FONT=verdana,geneva,lucida,'lucida grande',arial,helvetica,sans-serif]