Trouble calculating percentage in C++ dice program

[d0ugg]

I'm writing a program that will have to roll the dice A and dice B one million times, and calculate the percentage of times that the dies will be equal.

I'm having trouble to figure out how the percentage will work.

Here is my code:

 
#include <ctime>
#include <iostream>
using namespace std;
 
const double roll = 1000000;
 
int rolldie() //statement will give u 6
{
return (rand()%6+1);
}
 
void Randomize() 
{
srand( (unsigned)time( NULL ) ) ;
}
 
int main()
{
    int diceA;
    int diceB;
    int totals;
    int i;
    cout << "Rolling dices one million times\n";
    Randomize();
 
    for(i=0;i<roll;i++)
    {    
        diceA = rolldie();
        diceB = rolldie();
        int    totals = diceA + diceB;
        totals++;
    }
 
    if(diceA==diceB)
    {
        cout << "Doubles occurred" << totals / 1000000 << "percent of the time.";
    }
 
    return 0;
}
 

Thanks in advance,

Doug

[Studlyami]

void randomize(int *diceA, int *diceB)
{
srand((unsigned)+time(NULL));
*diceA = rand() %6+1;
srand((unsigned)+time(NULL));
*diceB = rand() %6+1;
}
 

you only need to do the srand once.

int verify_1(int diceA, int diceB)
{
int roll;
if(diceA==diceB)
roll++;
return roll;
}
 

here you initiate roll. every time you call this function roll gets reset. You are also not initializing roll to 0. int roll = 0; if not when you do roll++ you will get a messed up value.

[d0ugg]

Okay, thanks.
It looks like this now

int verify_1(int diceA, int diceB)
{
    int roll=0;
    if(diceA==diceB)
    roll++;
    return roll;
}
 

But how do I initialize it from the different number everytime?
Example(Roll=1, roll=2,roll=3.. etc)

~doug

[Studlyami]

sorry i didn't make myself clear. You only want to initialize roll once, but what is happening is every time you call that function it will initialize roll. you want a function like that you will need to pass in roll by reference.

void verify_1(int diceA, int diceB, int *roll)
{
    if(diceA==diceB)
    *roll++;
}
 

then in main before you do the for loop initialize roll to zero

int roll = 0;

[d0ugg]

Do you mean

int verify_1(int diceA, int diceB, float *roll)
{
    if(diceA==diceB)
    *roll++;
return *roll;
}
 

??
Because the compiler say that it has to return a value...

~doug

[Studlyami]

I played with your code for a bit and it was giving me problems so i decided to make it simple and put it in main. Here is the basic program, then you can try to put it into separate functions as you see fit.

#include <iostream>
#include <ctime>
using namespace std;
 
int main()
{
    srand( (unsigned)time( NULL ) ) ;
 
    int diceA = 0; //will get dicea value
    int diceB = 0; // will get diceb value
    int DoubleTotal = 0; //keeps track each time we get a dobule
 
    for(int i = 0; i<1000000; i++)
    {
        diceA = rand()%5 +1; //value 1-6
        diceB = rand()%5 +1; //value 1-6
        if(diceA==diceB)
        {   
            DoubleTotal++;
        }
    }
    cout<<"The dice were equal " << DoubleTotal <<" Times\n";
 
    return 0;
}
 

[d0ugg]

Thanks for the support,
but it is suppose to give the percentage of times that it happened.. But anyways, thanks!

[Studlyami]

Your Welcome. The percentage is just a simple math element at the end. You were really close at one point, you only needed to change like 2 lines, but then you split them up into functions and got confused again. I hope you can follow the logic and now that you have a working main try to split it up into the functions that you wanted.

[JosAH]

Thanks for the support,
but it is suppose to give the percentage of times that it happened.. But anyways, thanks!

Sure, that's step 2; do you get an acceptible number for the number of times the
dice rolls were equal? e.g. total = 1,000,000, equals = 166,667.

kind regards,

Jos

[d0ugg]

Hello!

Thank you so much for the help everyone..

Have a good Sunday! ;)

~doug