quick sort problem .. made the code function correctly .

SUNIL GUTTA

Hi

display unsored records first and then display sorted record using quick sort (according to ID). alsdeo repeat the above on three sets of student records.Its keep getting Error, but i dont have Idea~ please help me and check my code

#ifndef pro5_H
#define pro5_H

#include
#include
#include
#include

using namespace std;

class Student
{
private:
string nam;
int iden;
double grade;
string address;
int test1;
int test2;
int test3;
int test4;
int test5;
int test6;
int test7;
int test8;
int test9;
int test10;

public:
void setRecord( string name, int ID, double GPA, string addr, int t1,int t2,int t3,int t4,int t5,int t6,int t7,int t8,int t9,int t10);

void print();
int partition( vectorarray,int start, int end);
void quicksort(vectorarray, int start, int end);
void swap(Student &st1, Student &st2)

};

void Student::setRecord( string name, int ID, double GPA, string addr, int t1,int t2,int t3,int t4,int t5,int t6,int t7,int t8,int t9,int t10)
{

nam=name;
iden=ID;
grade=GPA;
address=addr;
test1=t1;
test2=t2;
test3=t3;
test4=t4;
test5=t5;
test6=t6;
test7=t7;
test8=t8;
test9=t9;
test10=t10;
}

int Student::partition(vector array,int first, int end)
{

int pivot, index, mid;
swap(array[first], array[mid]);
index=first;
pivot=array[first].iden;
for(int i= first+1; i<=end;i++)
{
if(array[i].iden{
index++;
swap(array[index],array[i]);

}
}
swap(array[first],array[index]);
return index;

}

void Student::quicksort(vector array,int first, int end)
{
int temp;
if(first< end)
{
temp=partition(array,first,end);
quicksort(array, first, temp-1);
quicksort(array, temp+1, end);
}
}
void swap(Student &st1, Student &st2)
{
Student temp= st1;
st1=st2;
st2=temp;
}

void Student::print()
{

cout<<

}
#endif
#include "pro5.h"
#include
#include
#include

using namespace std;

int main()
{
Student v[20];
vectorV;
v[0].setRecord("Ryan",1234,3.2, "Austin",50,90,80,57,87,98,87,39,70,89);
v[1].setRecord("Joo", 2345,3.4, "Dallas",56,87,67,98,67,90,56,45,67,84);
v[2].setRecord("Choo",3452,3.4, "Austin",76,90,89,90,93,90,98,90,99,76);
v[3].setRecord("Jay", 4123, 2.2, "San Marcos",45,67,56,44,34,23,76,54,34,43);
v[4].setRecord("Ryan",2345,4.0,"Houston", 34,25,56,78,72,81,67,89,67,56);
v[5].setRecord("koo", 3456,2.8,"Austin", 36,23,44,67,54,76,34,56,43,23);
v[6].setRecord("Lee", 9808,3.1,"Dallas",45,65,76,34,87,54,67,76,89,56);
v[7].setRecord("Kim", 7634,2.3,"Houston",45,78,97,67,89,90,89,99,87,65);
v[8].setRecord("Lisa",4560,3.5,"Dallas",67,89,90,87,89,78,67,56,90,87);
v[9].setRecord("Eric",9087,3.2,"Austin",34,56,78,87,98,67,78,67,78,87);
v[10].setRecord("Jean",8763,2.4,"Dallas",34,90,98,96,90,87,85,65,74,70);
v[11].setRecord("Bryan",7834,3.2,"Houston",87,87,89,87,67,89,67,76,76,56);
v[12].setRecord("Emi",9823,3.1,"Kyle",97,67,88,87,67,89,78,98,56,88);
v[13].setRecord("Tony",3423,3.0,"Corpus", 87,54,66,45,34,89,87,56,89,90);
v[14].setRecord("Tom",4567,2.4,"Plano", 54,67,54,78,98,90,778,87,49,87);
v[15].setRecord("Tylor",4321,1.8,"Dallas",34,43,34,56,12,23,0,0,12,43);
v[16].setRecord("Leah",2367,2.1,"Austin",43,56,78,99,87,65,43,44,78,65);
v[17].setRecord("Diana",5664,2.7,"Houston",32,56,87,97,67,87,98,67,67,78);
v[18].setRecord("Derrick",7964,2.1,"Plano",54,67,87,56,45,78,98,65,86,89);
v[19].setRecord("Corry",2317,3.3,"San Antonio",34,78,90,87,89,67,85,87,89,65);
//v[20].setRecord("Ray",1235,3.8,"Austin",87,89,98,78,89,90,98,87,90,78);
for(int i=0;i<20;i++)
{
v[i].print();
V.push_back(v[i]);
quicksort(V.push_back(v[i]), 0,v[i]);
cout<<"Sorted by Studnet ID: "<cout<<"____________________________________________"<cout<v[i].print();
}

system("PAUSE");

return 0;
}

Cheers
Have a nice day

4 Replies

Know the answer? Post it — somebody with the same question will find it here.

Vulpes13y ago
Accepted answer
Well, it's not a bad effort but I've had to make a number of changes to get it to compile and run correctly.

The main points are that:

1. partition, quicksort and swap should all be static methods of the Student class as they don't depend on the 'current' instance.

2. The Vector needs to be passed by reference to the partition and quicksort methods so that the changes are persisted to the calling code.

I've tried to highlight the lines where changes were made but may have missed some:

/* pro5.h */

#ifndef pro5_H
#define pro5_H

#include
#include
#include
#include
#include // ** added this include

using namespace std;

class Student
{
private:
string nam;
int iden;
double grade;
string address;
int test1;
int test2;
int test3;
int test4;
int test5;
int test6;
int test7;
int test8;
int test9;
int test10;

public:
void setRecord( string name, int ID, double GPA, string addr, int t1,int t2,int t3,int t4,int t5,int t6,int t7,int t8,int t9,int t10);

void print();
static int partition( vector& array, int start, int end); // ** made this static and passing Vector by ref
static void quicksort(vector& array, int start, int end); // ** made this static and passing Vector by ref
static void swap(Student &st1, Student &st2); // ** added semi-colon at end and made static

};

void Student::setRecord( string name, int ID, double GPA, string addr, int t1,int t2,int t3,int t4,int t5,int t6,int t7,int t8,int t9,int t10)
{

nam=name;
iden=ID;
grade=GPA;
address=addr;
test1=t1;
test2=t2;
test3=t3;
test4=t4;
test5=t5;
test6=t6;
test7=t7;
test8=t8;
test9=t9;
test10=t10;
}

int Student::partition(vector& array,int first, int end) //** Vector passed by ref
{

int pivot, index, mid;
mid = (first + end)/2; //** added this line
swap(array[first], array[mid]);
index=first;
pivot=array[first].iden;
for(int i= first+1; i<=end;i++)
{
if(array[i].iden
{
index++;
swap(array[index],array[i]);
}
}
swap(array[first],array[index]);
return index;

}

void Student::quicksort(vector& array,int first, int end) //** vector passed by ref
{
int temp;
if(first< end)
{
temp=partition(array,first,end);
quicksort(array, first, temp-1);
quicksort(array, temp+1, end);
}
}

void Student::swap(Student &st1, Student &st2) //** added Student:: & Vector by ref
{
Student temp= st1;
st1=st2;
st2=temp;
}

void Student::print()
{

cout<
<

}
#endif

/* Students.cpp or whatever it's called */

#include "pro5.h"
#include
#include
#include

using namespace std;

int main()
{
Student v[20];
vectorV;
v[0].setRecord("Ryan",1234,3.2, "Austin",50,90,80,57,87,98,87,39,70,89);
v[1].setRecord("Joo", 2345,3.4, "Dallas",56,87,67,98,67,90,56,45,67,84);
v[2].setRecord("Choo",3452,3.4, "Austin",76,90,89,90,93,90,98,90,99,76);
v[3].setRecord("Jay", 4123, 2.2, "San Marcos",45,67,56,44,34,23,76,54,34,43);
v[4].setRecord("Ryan",2345,4.0,"Houston", 34,25,56,78,72,81,67,89,67,56);
v[5].setRecord("koo", 3456,2.8,"Austin", 36,23,44,67,54,76,34,56,43,23);
v[6].setRecord("Lee", 9808,3.1,"Dallas",45,65,76,34,87,54,67,76,89,56);
v[7].setRecord("Kim", 7634,2.3,"Houston",45,78,97,67,89,90,89,99,87,65);
v[8].setRecord("Lisa",4560,3.5,"Dallas",67,89,90,87,89,78,67,56,90,87);
v[9].setRecord("Eric",9087,3.2,"Austin",34,56,78,87,98,67,78,67,78,87);
v[10].setRecord("Jean",8763,2.4,"Dallas",34,90,98,96,90,87,85,65,74,70);
v[11].setRecord("Bryan",7834,3.2,"Houston",87,87,89,87,67,89,67,76,76,56);
v[12].setRecord("Emi",9823,3.1,"Kyle",97,67,88,87,67,89,78,98,56,88);
v[13].setRecord("Tony",3423,3.0,"Corpus", 87,54,66,45,34,89,87,56,89,90);
v[14].setRecord("Tom",4567,2.4,"Plano", 54,67,54,78,98,90,778,87,49,87);
v[15].setRecord("Tylor",4321,1.8,"Dallas",34,43,34,56,12,23,0,0,12,43);
v[16].setRecord("Leah",2367,2.1,"Austin",43,56,78,99,87,65,43,44,78,65);
v[17].setRecord("Diana",5664,2.7,"Houston",32,56,87,97,67,87,98,67,67,78);
v[18].setRecord("Derrick",7964,2.1,"Plano",54,67,87,56,45,78,98,65,86,89);
v[19].setRecord("Corry",2317,3.3,"San Antonio",34,78,90,87,89,67,85,87,89,65);
//v[20].setRecord("Ray",1235,3.8,"Austin",87,89,98,78,89,90,98,87,90,78);
for(int i=0;i<20;i++)
{
v[i].print();
V.push_back(v[i]);
} // ** ended for loop here

Student::quicksort(V, 0, V.size() - 1); //** added Student:: and changed arguments
cout<<"\nSorted by Student ID: "<
cout<<"____________________________________________"<
cout<
for(int i=0;i<20;i++) //** new for loop introduced
{
V[i].print(); //** printing Vector elements
}

system("PAUSE");

return 0;
}
SUNIL GUTTA13y ago
yes i will look into that and if any further issues will get back to you friend :)

Ty so much

Have a nice day
Vulpes13y ago
Make sure that the implementation of your swap function is preceded by Student::

If it isn't, then the compiler will think it's a global function rather than a member function of the Student class and you'll then get an undefined reference error in the Student::partition function because it will appear that swap is being used before it's been defined.
SUNIL GUTTA13y ago
Dude .. its keep saying undefine reference swap func .. .. any ideas ?? ANd im keepg getting error on partition function too