2D Array & random numbers

I've got a two dimensional array which needs the first and third rows to match. In a "for" loop, I'm creating a random number (0-9)and assigning it to the first element in the array, and then incrementing the column element and repeating the process, giving me four random numbers in row1 (element[0]). Here's what I'm working with:

Code:

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int i;
int Game[3][4] = {0};

for (i=0; i<=3; i++)
{
        Game[0][i] = rand() % 10;
        Game[2][i] = Game[0][i];
}

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Is there a way to set one row equal to another without looping through the two as I have here? Also, each time I run this piece of code I get the same "random" numbers. I tried using randomize() and random() but couldn't make it work. I kept getting erros that randomize and random were not declared variables. How can I ensure the numbers I'm getting differ each time?

You need to seed the random number generator to get a random sequence.

Use: srand( (unsigned)time( NULL ) );

This starts the generator based on the computers clock.

To copy a row in an array yo do need to copy each element individually.

Just noticed that you initialise the array with { 0 }.

You probably know this, but that only sets Game[0][0] = 0

The remainder of the array will have values that are undetermined, in a debug build, these might be 0, but a release build they could be anything.

I haven't tried using srand() before. Here's and exmaple I pulled out of a book, which I tried to adapt to my code. I get teh same undeclared variable errors though.

Code:

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#include <time.h>
#include <stdlib.h>
#include <iostream.h>

int main()
{
        int i;

        randomize();

        for (i=1; i<5; i++)
        {
                cout << "\n" << random(10);
        }

        return 0;
}

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Quote:

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Originally posted by Dave McLelland
Just noticed that you initialise the array with { 0 }.

You probably know this, but that only sets Game[0][0] = 0

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Not true. If there are fewer entries in the initialization list than entries in the array, the remaining elements are set to 0.

Regards,

Paul McKenzie

You are right of course. It says so in the ARM.

Use a vector

Quote:

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Use a vector

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Sorry, I don't know what that is or how to use it.