output is not appear

[shamila08]

Hello, dear all!
Below is heap algorithm. the problem is the output is not appear. How to fix it?

#include <stdio.h>
#include <iostream>
using namespace std;
int *Value;
int N;

void read (int N)
{	int i;
		for (i = 0; i< N; i++)
		{ cout << Value[i] << "";
		}

}
void swap(int i,int j) 
{
    int t;
    t=Value[i]; 
    Value[i]=Value[j]; 
    Value[j]=t;
}
void HeapPermute(int N) 
{    int i;
     read (N);
	for (i=0;i<N;i++) {	    
	    HeapPermute(N-1);
	if (N%2 == 1) 
	    swap(0,N-1);
	else           
	    swap(i,N-1);
	}
 }
void initiate (int N)
{ int i;
	for(i=0; i<N; i++)
	{
		Value[i]=i+1;
	}
}

int main() 
{
   	cout << " Enter the Size of elements ";
	cin >> N;
	initiate (N);
       HeapPermute(N);
}

[Ancient Dragon]

between lines 45 and 46 add a line: cin.get(); to make the program stop before exiting.

delete line 1 -- stdio.h -- its not needed in your program.

[shamila08]

still doesn't work.
the output as follows:
Enter the Size of element 4
Press any key to continue . . ..

[Salem]

> int *Value;
Where does this point?
Answer, nowhere.

You need to allocate some space in your initialise function.

[shamila08]

i declare it as follows:

#include <iostream>
using namespace std;
int *Value;
int N;

[Salem]

And you initialise it NOWHERE!

Back to you.

[shamila08]

you mean i have to write it as follows:

#include <iostream>
using namespace std;
int N;

void read (int *Value ,int N)
{	int i;
		for (i = 0; i< N; i++)
		{ cout << Value[i] << "";
		}

}
void swap(int *Value,int i,int j) 
{
    int t;
    t= Value[i]; 
    Value[i]=Value[j]; 
    Value[j]=t;
}
void HeapPermute(int *Value,int N) 
{    int i;
     read (Value, N);
	for (i=0;i<N;i++) {	    
	    HeapPermute(Value,N-1);
	if (N%2 == 1) 
	    swap(Value,0,N-1);
	else           
	    swap(Value,i,N-1);
	}
 }
void initiate (int *Value,int N)
{ int i;
	for(i=0; i<N; i++)
	{
		Value[i]=i+1;
	}
}

void main(int*Value) 
{
   	cout << " Enter the Size of element ";
	cin >> N;
	initiate (Value, N);
		 HeapPermute(Value, N);
		 cin.get();
}

but still doesn't work

[stilllearning]

Ok, first of all ... you CANNOT define your main function this way. Read this.

Its either

int main(){

  return 0;
}

or

int main(int argc, char* argv[]){

  return 0;
}

You need to allocate space to your int array Value and then pass it in. How else is it going to store those values you are assigning it ?

Do something like this :

int* Value;

Value = new int[N]; /* here N is the total number of elements in your array */

Do NOT forget to clean up the allocated memory by deleting it before you exit your program.

[shamila08]

You mean like this:

int main() 
{
   	cout << " Enter the Size of element ";
	cin >> N;
	if (N >0 && N<=100){
		int *Value = new int [N];
		initiate (Value, N);
		 HeapPermute(Value, N);
		 delete [] Value;
	}
}

[stilllearning]

Yeah, that should work. You probably also want to throw some kind of an error if N is out of bounds. And don't forget the "return 0" at the end of main().