Count how many votes a number has

[glasseater]

Hi,

I am wondering how would I go about counting the amount of votes a certain number has in an array. I have 100 random numbers between 1-3 and I need to count how many each each number has for example:

Number 3 was voted for x amount of times

I know it would be a for loop but I'm not sure how its done.

This is the code I have so far.

  void gen(int x[]) {
    for (int i = 1; i < 1000; i++)
        x[i] = 1 + rand() % 3;
    }

void result(int x[]) {
    for (int i = 1; i < 1000; i++)
        cout << " " << x[i] << " ";
}

int main() {
    
    int random[1000];
    gen(random);
    srand((unsigned)time(NULL));
    
    result(random);
    
    return 0;
}

Thank you in advance

[Ganado]

Array indices start at 0, not 1.
You should change your loops to
for (int i = 0; i < 1000; i++)

Also, call srand before you call gen.

If you know that only a set amount of numbers are possible (1, 2, 3), then just make an array of that size to keep track of it.

#include <iostream>
#include <ctime>
#include <cstdlib>

const int Num_Results = 3;

void gen(int x[], int results[]) {
    for (int i = 0; i < 1000; i++) {
        x[i] = 1 + rand() % Num_Results;
        results[x[i] - 1]++; // x[i] - 1 is either a 0, 1, or 2.
    }
}

void result(int x[], int results[]) {
    for (int i = 0; i < Num_Results; i++)
    {
        std::cout << "The number " << i + 1 << " occurred " << results[i] << " times.\n";   
    }
    
    // Print the actual array here if you want to (pass in the random array)
}

int main() {
    
    int random[1000];
    int results[Num_Results] = {}; // initialize all numbers to 0
    
    srand((unsigned)time(NULL));
    
    gen(random, results);
    result(random, results);    
    
    return 0;
}

[glasseater]

Thank you! I see. This is better than what I had now my computer doesn't lag when printing out all the numbers.

[SamuelAdams]

If you sort the numbers first, then you can just count how many of each identical number you have and go to the next larger or smaller number.

[mzimmers]

SamuelAdams: I don't think sorting is appropriate here. It would almost certainly take more CPU (probably MUCH more) than simply iterating through the array and updating a few counters.