Question

USING C++:

Write a function that given a 2D dynamic array of integers, will return the number of elements whose absolute value is smaller than a given value x. The function should take as arguments (in this order):

• a pointer to the array (i.e., 2D dynamic array)
• the number of rows
• the number of columns
• the given value

The function should return

• the number of elements smaller in absolute value than epsilon

E.g. if A={{0.2, -0.1, 3.4},{4.4, 0, -2}} and x=0.3,  then 
smallElementCount(A, 2,3, x) will return 3 (0.2, -0.1, and 0  are all less than 0.3 in absolute value).

The function prototype is given below

int smallElementCount(double **, int, int, double);

Answer 1

#include <iostream>

using namespace std;

int smallElementCount(double **, int, int, double);

int main() {
    double **A = new double*[2];
    A[0] = new double[3];
    A[0][0] = 0.2;
    A[0][1] = -0.1;
    A[0][2] = 3.4;
    A[1] = new double[3];
    A[1][0] = 4.4;
    A[1][1] = 0;
    A[1][2] = -2;
    cout << smallElementCount(A, 2, 3, 0.3) << endl;
    return 0;
}

int smallElementCount(double **arr, int rows, int cols, double x) {
    double abs_val;
    int count = 0;
    for (int i = 0; i < rows; ++i) {
        for (int j = 0; j < cols; ++j) {
            abs_val = arr[i][j];
            if (abs_val < 0) {
                abs_val *= -1;
            }
            if (abs_val < x)
                ++count;
        }
    }
    return count;
}