Jagged Arrays in C++

// C++ Program to implement  Jagged Array
// 1st way: static arrays
#include <iostream>
using namespace std;

int main()
{
    // create 3 row arrays having different sizes
    // ( no ofcolumns)
    int row1[] = { 1, 2, 3, 4 };
    int row2[] = { 5, 6 };
    int row3[] = { 7, 8, 9 };

    // storing base address of each row array
    int* jagged[] = { row1, row2, row3 };

    int sizes[] = { 4, 2, 3 };

    cout << "elements in matrix form as follow" << endl;
    for (int i = 0; i < 3; i++) {

        // getting current(ith) row
        int* ptr = jagged[i];

        for (int j = 0; j < sizes[i]; j++) {
            // for ith row having sizes[i] no. of
            // columns

            cout << *(ptr + j) << " ";
            // *ptr have base address
            // adding j means access jth
            // element for particular(ith) row
        }
        cout << endl;
    }

    return 0;
}

// C++ Program to implement Jagged array
// 2nd way: Dynamic 2D array
#include <iostream>
using namespace std;

int main()
{
    // system("cls");

    int row, col;
    row = 3;

    // Create Row Array- dynamic array of pointers
    int** arr = new int*[row];
    int sizes[] = { 4, 2, 3 };
    // int *sizes= new int[row];
    // if taking row as input

    // no of columns for each row as input from user
    for (int i = 0; i < row; i++) {
        /*
        cin>>col;        //if col is taken as input
        / sizes[i]=col;
        // store each col number in size ( if row and col
        // are taken as input)
        */

        *(arr + i) = new int[sizes[i]];
        // creating column of sizes[i] for each row
    }

    // input from user
    int num = 1;
    for (int i = 0; i < row; i++) {
        for (int j = 0; j < sizes[i]; j++) {
            // cin>>arr[i][j];    //if user want to input
            arr[i][j] = num++;
        }
    }

    cout << "elements in matrix form as follow" << endl;
    for (int i = 0; i < row; i++) {
        for (int j = 0; j < sizes[i]; j++) {
            cout << arr[i][j] << " ";
        }
        cout << endl;
    }

    return 0;
}