Esercizio Matrici (1)

/*
 * Creare due array di interi, A e B, con elementi e lunghezza casuale, se tutti gli elementi
 * di A sono distinti calcolare una matrice mxn contenente il prodotto AxB altrimenti restituire
 * la matrice identità.
 *
 */

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

 using namespace std;

 // core
 int get_random_int(int min, int max);
 int *random_int_array(int size, int min, int max);
 bool check_duplicates(int *array, int size);
 int **identity_matrix(int size);
 int **matrix_multiplication(int *matrix_1, int *matrix_2, int h, int w);

 // extra
 void print_array(int *array, int size);
 void print_matrix(int **matrix, int h, int w = 0);

 int main()
 {
    srand(time(NULL));

    int n = get_random_int(1, 3), *A,
        m = get_random_int(1, 3), *B;

    A = random_int_array(n, 1, 3);
    cout << "A: "; print_array(A, m); cout << endl;

    B = random_int_array(m, 1, 3);
    cout << "B: "; print_array(B, n); cout << endl;

    if(check_duplicates(A, m)) {
        cout << "La matrice A ha duplicati, stampo la matrice identita'" << endl;
        print_matrix(identity_matrix(m * n), m * n);
    } else {
        cout << "Moltiplicazione AxB" << endl;
        print_matrix(matrix_multiplication(A, B, m, n), m, n);
    }

    return 0;
 }

 int get_random_int(int min, int max)
 {
    max -= min - 1;
    return int(rand() % max + min);
 }

 int *random_int_array(int size, int min, int max)
 {
    int *new_array = new int[size];
    for(int i = 0; i < size; i++) {
        new_array[i] = get_random_int(min, max);
    }
    return new_array;
 }

 bool check_duplicates(int *array, int size)
 {
    for(int i = 0; i < size; i++) {
        for(int j = 0; j < size; j++) {
            if(i == j) continue;
            if(*(array + i) == *(array + j)) return true;
        }
    }
    return false;
 }

 int **identity_matrix(int size)
 {
    int **matrix = new int*[size];

    for(int i = 0; i < size; i++) {
        matrix[i] = new int[size];
        for(int j = 0; j < size; j++)
            matrix[i][j] = i == j ? 1 : 0;
    }

    return matrix;
 }

 int **matrix_multiplication(int *matrix_1, int *matrix_2, int h, int w)
 {
    int **matrix = new int*[h];

    for(int i = 0; i < h; i++) {
        matrix[i] = new int[w];
        for(int j = 0; j < w; j++) {
            matrix[i][j] = matrix_1[i] * matrix_2[j];
        }
    }

    return matrix;
 }

 void print_array(int *array, int size)
 {
    for(int i = 0; i < size; i++) {
        if(!i) cout << '[';
        cout << *(array + i) << (i == size-1 ? ']' : '\t');
    }
    return;
 }

 void print_matrix(int **matrix, int h, int w)
 {
     if(!w) w = h;
     for(int i = 0; i < h; i++) {
        for(int j = 0; j < w; j++) {
            cout << matrix[i][j] << '\t';
        }
        cout << endl;
     }
     return;
 }