Thread: Help with a program...

Hi! I've been interested in programming for a while now, so a couple of months ago a bought a book so I could teach myself. The thing is, I'm having some trouble with an excercise. It's objective is to build a program that, using arrays, shows the results of throwing two dice 36.000 times. I have written up this code:

Code:

// Ej. 6.19
// two dice throws

#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#define N 13

// main starts program
int main()
{
    int total; // total of two dice throws
    int throws; // counter for number of throws
    int frec[N]; // frequency of dice throws
    int start; // user starts program with this
    
    srand( time (NULL) ); // random number generator
    
    printf( "\nProgram to simulate the throwing of 2 dice 36000 times\n" );
    
    
    do
    {
        printf( "To start, type 1.\n" );
        printf( "Otherwise, type any other number to exit.\n" );
        scanf( "%d", &start );
        
        if( start != 1 )
            break;
        
        // throws dice 36000 times
        for( throws = 1; throws <= 36000; throws++ )
        {
            total = ( 1 + ( rand() % 6 ) ) + ( 1 + ( rand() % 6 ) );
            frec[ total ]++;
        } // end of for
        
        printf( "%s%17s\n", "Total", "Frequency" );
        
        for( total = 1; total < N; total++ )
        {
            printf( "%5d%17d\n", total, frec[total] );
        } // end of for
    } // end of do
    while( start  == 1 ); 
    
    return 0; // successfull end of program
} // end of main

But, the actual program running is really strane. The compiler (Dev-C++) didn't give any errors or warnings or anything.

Code:

Program to simulate the throwing of 2 dice 36000 times
To start, type 1.
Otherwise, type any other number to exit.
1
Total        Frequency
    1       2009284272
    2          2294727
    3       2009286276
    4       2009148402
    5          2297449
    6       2009251663
    7          2299872
    8       2009289304
    9       2009149352
   10             2980
   11       2009248549
   12       2009306949
To start, type 1.
Otherwise, type any other number to exit.

Huge numbers.... No matter how many times I run it, even with srand, the numbers are about the same...
Could anyone tell me what's wrong with my code, please?

Make sure you initialize all your array elements to zero.

Now it works perfectly! Thanks! I've always overlooked that... I've just started learning to program, anyway.

Also you will never have a total of one because the lowest roll for each die is a one, and one plus one is two.