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help About Random

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Join Date: Feb 2009

Posts: 2

Reputation: aminpost is an unknown quantity at this point

Solved Threads: 0

aminpost

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Newbie Poster

help About Random

Feb 27th, 2009

i have a class with 10 object and each object have a random position like (x,y)
now i wand a code that do not put object in same position
please complete my code

 Help with Code Tags 
 C++ Syntax (Toggle Plain Text) 
#include <iostream.h>
#include <time.h>
#include <stdlib.h>
 
class chess{
 
public :
	chess();
private :
	int x;
	int y;
};
 
 
 
chess::chess()
{
x=rand()%15+1;    //rand()%max+min will give values from min to min+max-1
y=rand()%15+1;
}
 
main()
{
chess a[10];
}
#include <iostream.h>
#include <time.h>
#include <stdlib.h>

class chess{

public :
	chess();
private :
	int x;
	int y;
};



chess::chess()
{
x=rand()%15+1;    //rand()%max+min will give values from min to min+max-1
y=rand()%15+1;
}

main()
{
chess a[10];
}

•

Join Date: Aug 2008

Posts: 83

Reputation: nmaillet is an unknown quantity at this point

Solved Threads: 18

nmaillet

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Junior Poster in Training

Re: help About Random

Feb 27th, 2009

You need to set the rand seed value, use srand() . Unlike Java and C# the seed value, when not set, is the same every time it is run. I suggest using the current time to set the seed value.

•

Join Date: Feb 2009

Posts: 2

Reputation: aminpost is an unknown quantity at this point

Solved Threads: 0

aminpost

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Newbie Poster

Re: help About Random

Feb 27th, 2009

•

Originally Posted by nmaillet

You need to set the rand seed value, use srand() . Unlike Java and C# the seed value, when not set, is the same every time it is run. I suggest using the current time to set the seed value.

now what should i do?

 Help with Code Tags 
 C++ Syntax (Toggle Plain Text) 
#include <iostream.h>
#include <time.h>
#include <stdlib.h>
 
class chess{
 
public :
	chess();
private :
	int x;
	int y;
};
 
 
 
chess::chess()
{
x=rand()%15+1;    //rand()%max+min will give values from min to min+max-1
y=rand()%15+1;
}
 
main()
{
srand((unsigned)time(NULL));
chess a[10];
}
#include <iostream.h>
#include <time.h>
#include <stdlib.h>

class chess{

public :
	chess();
private :
	int x;
	int y;
};



chess::chess()
{
x=rand()%15+1;    //rand()%max+min will give values from min to min+max-1
y=rand()%15+1;
}

main()
{
srand((unsigned)time(NULL));
chess a[10];
}

•

Join Date: Aug 2008

Posts: 83

Reputation: nmaillet is an unknown quantity at this point

Solved Threads: 18

nmaillet

Offline

Junior Poster in Training

Re: help About Random

Feb 27th, 2009

You can run it through a loop to check the other pieces to ensure that the randomly generated square is not already occupied.

•

Join Date: Oct 2008

Posts: 40

Reputation: seanhunt is an unknown quantity at this point

Solved Threads: 6

seanhunt

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Light Poster

Re: help About Random

Feb 28th, 2009

Help yes. Writing code for others, no, sorry ;P

Thanx...
Sean

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Join Date: Oct 2007

Posts: 794

Reputation: siddhant3s has much to be proud of

Solved Threads: 135

siddhant3s siddhant3s is offline

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Master Poster

Re: help About Random

Mar 1st, 2009

Create a static member in your class which is a bool type 2D array (call it say,current_pos) of 8X8 elements.
Each time you assign a Position to the object, be sure to mark the current_pos[x][y]=TRUE;
So, now you can keep track of what all postition are been ocupied.
Hence, as soon as your random() generates a new position, check whether that position is already occupied or not. If it is, tell him to generate another number and so on.

Since the array will be a static member, its value will be same for all the object of the class.

Last edited by siddhant3s; Mar 1st, 2009 at 9:37 am.

Siddhant Sanyam
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