Merge and QuickSort - stack overloaded - c++

Question

Helo everyone. :)
I have to write a program where I have 4 types of sorting: bubble-, insertion-, merge- i quick-sort.
Program has to sort points x,y in array of structures (random) by amount of total of their coordinates //e.g.: (1,3) is less than (0,6) because 1+3<0+6//. It saves sorted ones in this same array and also in txt file with time of sorting by each B,I,M,Q-sort.
Code from Merge and MergeSort:
void Merge(Structure *tab, int A, int sr, int Z)
{
Structure *tmp = new Structure[Z];
int i;
for (i = A; i <= Z; ++i)
{
tmp[i] = tab[i];
}
i = A;
int j = sr + 1;
int q = A;
while (i <= sr && j <= Z)
{
if (Compare(tab, i, j)) //'Compare' tells if total of coordinates from tab[i] is bigger than total from tab[j]
{
tab[q] = tmp[i];
++j;
}
else
{
tab[q] = tmp[j];
++i;
}
++q;
}
if(i <= sr)
{
while (i <= sr)
{
tab[q] = tmp[i];
++i;
++q;
}
}
else
{
while(j <= Z)
{
tab[q] = tmp[j];
++j;
++q;
}
}
delete[] tmp;
}
void MergeSort(Structure *tab, int A, int Z)
{
int sr = (A + Z)/2;
if(A < Z)
{
MergeSort(tab, A, sr);
MergeSort(tab, sr + 1, Z);
Merge(tab, A, sr, Z);
}
}
And to QuickSort:
int DivideQS(Structure *tab, int A, int Z)
{
Structure tmp;
Structure pivot = tab[A]; // first el. for pivot (A=0)
int i = A, j = Z; //indexes in array
while (true)
{
while (Compare(tab, j, A))
j--;
while (!Compare(tab, i, A)) // until elements are lower than pivot, that's this '!' for
i++;
if (i < j) // swap when i < j
{
tmp = tab[i];
tab[i] = tab[j];
tab[j] = tmp;
i++;
j--;
}
else
return j;
}
}
void QuickSort(Structure *tab, int A, int Z)
{
int dziel;
if (A < Z)
{
dziel = DivideQS(tab, A, Z);
QuickSort(tab, A, dziel);
QuickSort(tab, dziel+1, Z);
}
}
My problem is a stack. No matter how big I make this, it still goes overloaded. I can't manage this problem. I don't know if that's because of mistake in code or it's somewhere else. Bubble and Insertion work impeccable.
I was looking for solving on many sites, in my language and foreign ones (I'm Pole), and modificating code in so many ways but still have no clue what to do.
Help me, please.
===================================
How could I be so blind! Thank you #user3187084. :D
But I think I went from bad to worse. Now I've received new error message:
Windows has triggered a breakpoint in Projekt_AiSD.exe.
This may be due to a corruption of the heap, which indicates a bug in Projekt_AiSD.exe or any >of the DLLs it has loaded.
This may also be due to the user pressing F12 while Projekt_AiSD.exe has focus.
The output window may have more diagnostic information.
And after that this showed to me: http://i40.tinypic.com/314qyl5.png
And this is code for checking:
#include <ctime>
#include <cstdlib>
#include <cstdio>
#include <Windows.h>
#include <string>
#include <fstream>
#include <sstream>
using namespace std;
struct Structure
{
int x;
int y;
};
bool Compare(Structure *tab, int i, int j)
{
if ( (tab[i].x + tab[i].y) > (tab[j].x + tab[j].y))
return true;
return false;
}
void LosujWspolrzedne(Structure* tab, int K)
{
srand(time(NULL));
for (int i = 0; i < K; i++)
{
tab[i].x = rand()%21;
tab[i].y = rand()%21;
}
//return;
}
void Save (Structure *tab, int K, string NazwaPliku)
{
ofstream zap(NazwaPliku);
for (int i = 0; i < K; i++)
{
zap << tab[i].x << ' ' << tab[i].y << endl;
}
zap.close();
}
void Load (Structure *tab, int K, string NazwaPliku)
{
ifstream wcz(NazwaPliku);
if (!wcz)
{
cout << "Can't open the file!!!" << endl;
exit(1);
}
for (int i = 0; i < K; ++i)
{
wcz >> tab[i].x >> tab[i].y;
}
wcz.close();
}
void Time(long long a, long long b, string NazwaPliku)
{
ofstream czas(NazwaPliku);
if (!czas)
{
cout << "Can't open the file!!!" << endl;
}
czas << (b - a) << " ms" << endl;
czas.close();
}
void CopyArray(Structure *tab, Structure *tab1, int K)
{
for (int i = 0 ; i < K ; i++)
{
tab1[i].x = tab[i].x;
tab1[i].y = tab[i].y;
}
}
void Call_MS(Structure *tab, int A, int K)
{
Load(tab, K, "1k.txt");
long long startTime = GetTickCount64();
MergeSort(tab, A, K-1);
long long endTime = GetTickCount64();
cout << (endTime - startTime) << "ms dla MergeSort" << endl;
Save(tab, K, "WartLos_MS_1k.txt");
Time(startTime, endTime, "WartLos_MS_1k_czas.txt");
}
void Call_QS(Structure *tab, int A, int K)
{
Load(tab, K, "1k.txt");
long long startTime = GetTickCount64();
QuickSort(tab, A, K-1);
long long endTime = GetTickCount64();
cout << (endTime - startTime) << "ms dla QuickSort" << endl;
Save(tab, K, "WartLos_QS_1k.txt");
Time(startTime, endTime, "WartLos_QS_1k_czas.txt");
}
const int MAX_EL = 30;
int _tmain(int argc, _TCHAR* argv[])
{
Structure *punkt = new Structure[MAX_EL];
void LosujWspolrzedne(Structure *punkt, int MAX_EL);
Structure *punkt1= new Structure[MAX_EL];
void CopyArray(Structure *punkt, Structure *punkt1, int MAX_EL);
delete[] punkt;
Save(punkt1, MAX_EL, "1k.txt");
cout<<"Start:"<<endl;
Call_MS(punkt1, 0, MAX_EL);
Call_QS(punkt1, 0, MAX_EL);
delete[] punkt1;
return 0;
}

Answer 1

You have MergeSort(tab, A, Z) inside MergeSort, so you always call itself with exact arguments
It should be MergeSort(tab, A, st)

Answer 2

You are using MergeSort(tab,A,Z) which call the same function again with same arguments which is will go one for infinite recursion hence error. You should only pass MergeSort(tab,A,sr) which will reduce your problem to half size.