problem with quicksort function

[beginner123]

i need to sort a list of 10 numbers using the QuickSort method but there are errors in the split function. All the < and > are underlined and say no operator "<" matches these operands

#include "stdafx.h"
using namespace std;

typedef struct 
 {
	int first;
	int last;
	int splitPt1;
	int splitPt2;
 }values ;

typedef values ItemType; 



void Split(ItemType values[],int first, int last,int& splitPt1, int& splitPt2);
void QuickSort (ItemType values[], int first, int last);

int _tmain(int argc, _TCHAR* argv[])
{
	int list[10];
	
	//code: get data to fill the collection
	cout << "Enter 10 positive integers for the list\n";
	for (int i = 0; i < 10; i++)
	cin >> list[i];
	

	return 0;
}

void Split(ItemType values[],int first, int last,int& splitPt1, int& splitPt2)
{
	ItemType splitVal = values[(first+last)/2],t;
   int i = first, j = last;
   while (values[i] < splitVal) i++;
	while (values[j] > splitVal) j--;
   while (i < j)
   {
      t = values[i];      values[i] = values[j]; 
      values[j] = t;
		i++;	
		j--;
	while (values[i] < splitVal) i++;
	while (values[j] > splitVal) j--;
   }
   if (i == j)
   {
      i++; j--;
   }
   splitPt1 = i;
   splitPt2 = j;
}

void QuickSort (ItemType values[], int first, int last)
{	
	int splitPt1, splitPt2;
	if (first < last)
	{
		Split(values, first, last, splitPt1, splitPt2);
		QuickSort(values, first, splitPt2);
		QuickSort(values, splitPt1, last);
	
	}

}

[beginner123]

anyone? please help

[coder777]

You're comparing structs with each other. What's the criteria that one struct is less/greater then the other?

If you want to do it in C you need functions such as greater(const ItemType &i1, const ItemType &i2) to tell what item is greater.

[beginner123]

i don't really understand could you show me?

[stridexr]

Where is your #include<iostream> ?

[beginner123]

in stdafx.h

[coder777]

What is this

typedef struct 
 {
	int first;
	int last;
	int splitPt1;
	int splitPt2;
 }values ;

typedef values ItemType;

good for? I don't see any use.

[beginner123]

I wasnt sure how to initialize all the values needed for the two functions

[coder777]

But you don't use it at all.

Drop that struct and replace ItemType with int and the compiler errors will go away

[beginner123]

i changed the code a bit

int list[10];
void Split(list[],int first, int last,int& splitPt1, int& splitPt2);
void QuickSort (ItemType values[], int first, int last);

int _tmain(int argc, _TCHAR* argv[])
{

	//code: get data to fill the collection
	cout << "Enter 10 positive integers for the list\n";
	for (int i = 0; i < 10; i++)
	cin >> list[i];
	

	return 0;
}

void Split(list[],int first, int last,int& splitPt1, int& splitPt2)
{
	list splitVal = values[(first+last)/2],t;
   int i = first, j = last;
   while (values[i] < splitVal) i++;
	while (values[j] > splitVal) j--;
   while (i < j)
   {
      t = values[i];      values[i] = values[j]; 
      values[j] = t;
		i++;	
		j--;
	while (values[i] < splitVal) i++;
	while (values[j] > splitVal) j--;
   }
   if (i == j)
   {
      i++; j--;
   }
   splitPt1 = i;
   splitPt2 = j;
}

void QuickSort (list[], int first, int last)
{	
	int splitPt1, splitPt2;
	if (first < last)
	{
		Split(values, first, last, splitPt1, splitPt2);
		QuickSort(values, first, splitPt2);
		QuickSort(values, splitPt1, last);
	
	}

basically i just changed ItemType to list but im still getting errors

[beginner123]

can someone please help?

[coder777]

If you want to keep 'ItemType'. It's okay

Then

#include "stdafx.h"
using namespace std;

typedef int ItemType; // ItemType is now int and it should compile



void Split(ItemType values[],int first, int last,int& splitPt1, int& splitPt2);
void QuickSort (ItemType values[], int first, int last);

int _tmain(int argc, _TCHAR* argv[])
{
	int list[10];
	
	//code: get data to fill the collection
	cout << "Enter 10 positive integers for the list\n";
	for (int i = 0; i < 10; i++)
	cin >> list[i];
	

	return 0;
}

void Split(ItemType values[],int first, int last,int& splitPt1, int& splitPt2)
{
	ItemType splitVal = values[(first+last)/2],t;
   int i = first, j = last;
   while (values[i] < splitVal) i++;
	while (values[j] > splitVal) j--;
   while (i < j)
   {
      t = values[i];      values[i] = values[j]; 
      values[j] = t;
		i++;	
		j--;
	while (values[i] < splitVal) i++;
	while (values[j] > splitVal) j--;
   }
   if (i == j)
   {
      i++; j--;
   }
   splitPt1 = i;
   splitPt2 = j;
}

void QuickSort (ItemType values[], int first, int last)
{	
	int splitPt1, splitPt2;
	if (first < last)
	{
		Split(values, first, last, splitPt1, splitPt2);
		QuickSort(values, first, splitPt2);
		QuickSort(values, splitPt1, last);
	
	}

} 

[beginner123]

ok thanks it compiles but how do i display the list after its been sorted? i know i will need to call the QuickSort function

[beginner123]

hello?

[coder777]

to display the list you just need to write loop like on line 17/18 and exchange 'cin >>' with 'cout <<'

[beginner123]

but i need the list to get sorted so how do i call the quicksort function to sort the list?

[coder777]

QuickSort(list, 0, 10); after line 18

[beginner123]

ok so heres what i added

QuickSort(list, 0, 10); 
cout << "sorted list is " << endl;
for (int list = 0; list < 10; list++)
cout << list;

but an error message comes up when i run it saying stack around variable 'list' was corrupted.
I tried the for loop using i instead of list but it still doesnt work

[coder777]

hm, ok it's 9 not 10: QuickSort(list, 0, 9);

[beginner123]

ok that got rid of the error message but the output isnt right

Enter 10 positive integers
22 54 12 1 8 7 4 2 98 5
sorted list is
0043FB7C 0043FB7C 0043FB7C 0043FB7C 0043FB7C 0043FB7C 0043FB7C 0043FB7C 0043FB7C 0043FB7C 
Press any key to continue . . .