Question

Write a code to initialize a 2D array with random integers (not has to be different). Write a function to count the number of cells that contain an even number within the 2D array.

C++

Answer 1

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

using namespace std;

#define ROWS 3
#define COLUMNS 4

int count_evens(int arr[ROWS][COLUMNS]) {
    int count = 0;
    for (int i = 0; i < ROWS; ++i) {
        for (int j = 0; j < COLUMNS; ++j) {
            if (arr[i][j] % 2 == 0) {
                ++count;
            }
        }
    }
    return count;
}

int main() {
    srand(time(NULL));
    // create and populate a 2d array with random data
    int arr[ROWS][COLUMNS];
    for (int i = 0; i < ROWS; ++i) {
        for (int j = 0; j < COLUMNS; ++j) {
            arr[i][j] = rand() % 100;
        }
    }
    // print array
    cout << "2D array is" << endl;
    for (int i = 0; i < ROWS; ++i) {
        for (int j = 0; j < COLUMNS; ++j) {
            cout << arr[i][j] << " ";
        }
        cout << endl;
    }
    // print number of evens
    cout << "Number of even numbers in array is " << count_evens(arr) << endl;
    return 0;
}