Adjacency Matrix and Adjacency Graph

// adjacency matrix and adjacency list

#include <iostream>
using namespace std;

void adjacency_matrix(int**, int);
void adjacency_list(int**, int);
void show_matrix(int**, int);
void show_list(int**, int);

int main() {
    cout << "How many vertices ? Number of Vertices: ";
    int number, **arr1, **arr2; cin >> number;

    arr1 = new int*[number]; // mamory allocation for n pointers
    adjacency_matrix(arr1, number); // input taken
    show_matrix(arr1, number); // show adjacency matrix

    cout << "\nAdjacency Matrix to List: " << endl;
    show_list(arr1, number);

    arr2 = new int*[number]; // mamory allocation for n pointers [for a different array]
    adjacency_list(arr2, number); // input taken
    show_list(arr2, number); // show adjacency list

    cout << "\nAdjacency List to Matrix: " << endl;
    show_matrix(arr2, number);

    cout << endl;
    return 0;
}

void adjacency_matrix(int **arr, int n) {
    cout << "\nGIVE YOUR MATRIX INPUT: [ " << n << " col. and rows ]" << endl;
    for (int i = 0; i < n; i++) {
        arr[i] = new int[n]; // memory allocation for n int(s) for each row
        for (int j = 0; j < n; j++) {
            cin >> arr[i][j];
        }
    }
}

void adjacency_list(int **arr, int n) {
    cout << "\nGIVE ADJACENT VERTICES FOR EACH VERTEX: " << endl;
    for (int i = 0; i < n; i++) {
        arr[i] = new int[n]; // memory allocation for n int(s) for each row
        for (int j = 0; j < n; j++)
            arr[i][j] = 0;
        cout << "\nTotal Vertices for " << i + 1 << ": "; int x; cin >> x;
        cout << "\nAdjacent Vertices: ";
        for (int j = 0; j < x; j++) {
            int m; cin >> m;
            arr[i][m - 1] = 1;
        }
    }
}

void show_matrix(int **arr, int n) {
    cout << "\nAdjacency matrix: " << endl;
    for (int i = 0; i < n; i++) {
        for (int j = 0; j < n; j++) {
            cout << arr[i][j] << " ";
        }
        cout << endl;
    }
}

void show_list(int **arr, int n) {
    cout << "\nAdjacency list: " << endl;
    for (int i = 0; i < n; i++) {
        cout << i + 1 << " -> ";
        for (int j = 0; j < n; j++) {
            if (arr[i][j] == 1)
                cout << j + 1 << " ";
        }
        cout << endl;
    }
}