C++ number generator outputs the same number

Question

I am making a program that simulates the rolling of dice 100 times, and keeps track of how many of each number have been rolled. The problem is the number generator keeps outputting the same number over and over. It adds it all together just fine, but it is just one number that is outputted. Here's the code:

#include <iostream>
#include <cstdlib>
#include <cmath>
using namespace std;

int Diceroll (int);
int main() {

    int num = 0, sum1 = 0, sum2 = 0, sum3 = 0, sum4 = 0, sum5 = 0, sum6 = 0;
    int i = 0, j = 100;

    for(int i = 0; i < j; i++) {
         num = 0;

         num = Diceroll(num);
         cout << num << endl;

         if(num == 1) {
             sum1 += 1;
         }
         else if(num == 2) {
             sum2 += 1;
         }
         else if(num == 3) {
             sum3++;
         }
         else if(num == 4) {
             sum4++;
         }
         else if(num == 5) {
             sum5++;
         }
         else if(num == 6) {
             sum6++;
         }
    }

    cout << "1 was rolled " << sum1 << " times." << endl;
    cout << "2 was rolled " << sum2 << " times." << endl;
    cout << "3 was rolled " << sum3 << " times." << endl;
    cout << "4 was rolled " << sum4 << " times." << endl;
    cout << "5 was rolled " << sum5 << " times." << endl;
    cout << "6 was rolled " << sum6 << " times." << endl;

    return 0;
}

int Diceroll (int num) {

    srand(time(0));

    num = (rand()%6) + 1; 

    return num;
}

Would be real nice if there was you know, actual indentation in this code. — Mad Physicist, Jan 10 '18 at 04:10
Don't seed the rng every time. Do it once in `main` and don't do it again. You're probably running in under a second, so the same seed leads to a repeated value. — Mad Physicist, Jan 10 '18 at 04:11
@AnthonySottile. 5 close votes, all with different duplicates, that's the goal. Probably possible to achieve. — Mad Physicist, Jan 10 '18 at 04:17
@MadPhysicist I found ~3 other questions that _could_ be dupe targets too. It honestly wouldn't surprise me :D — anthony sottile, Jan 10 '18 at 04:18
@MadPhysicist I changed the look of it so it had the proper indentation. — Genghis Khan, Jan 10 '18 at 04:19
@GenghisKhan. Thanks. It's a good question. You just aren't the first one to ask it. — Mad Physicist, Jan 10 '18 at 04:33
I would suggest using the `std's` `pseudo random number generators` that can be found in the `` header file since `c++11`. You can find more information about them here: http://en.cppreference.com/w/cpp/numeric/random as opposed to the less desirable `rand()` and `srand()` functions. — Francis Cugler, Jan 10 '18 at 06:03

C++ number generator outputs the same number

0 Answers0