Print a given matrix in zigzag form

Given a 2D array, print it in zigzag form. Examples : 

Input : 
        1    2   3   4   5
        6    7   8   9   10
        11   12  13  14  15
        16  17  18  19   20
Output :
1 2 3 4 5 10 9 8 7 6 11 12 13 14 15 20 19 18 17 16 


Input :
        10    24   32   
        50    6    17   
        99    10   11  
         
Output :
10 24 32 17 6 50 99 10 11

CPP

// C++ program to print
// matrix in zig-zag form
#include <iostream>
using namespace std;
const int MAX = 100;

    // Method to print matrix in zig-zag form
    void printZigZag(int row, int col, int a[][MAX])
    {
        int evenRow = 0; //starts from the first row
        int oddRow = 1; //starts from the next row

        while (evenRow<row)
        {
            for (int i=0;i<col;i++)
            {
                // evenRow will be printed
                        // in the same direction
                cout<<a[evenRow][i] << " ";
            }

            // Skipping next row so as
                // to get the next evenRow
            evenRow = evenRow + 2;

            if(oddRow < row)
            {
                for (int i=col-1; i>=0; i--)
                {
                // oddRow will be printed in
                    // the opposite direction
                cout<<a[oddRow][i] << " ";
                }
            }

            // Skipping next row so as
                // to get the next oddRow
            oddRow = oddRow + 2;
        }
    }

// Driver function
int main() {

    int r = 3, c = 5;
      int mat[][MAX] = { {1, 2, 3, 4, 5},
                         {6, 7, 8, 9, 10},
                         {11, 12, 13, 14, 15}};

        printZigZag(r , c , mat);
      return 0;
}

Java

// Java program to print matrix in zig-zag form
public class GFG
{
    // Method to print matrix in zig-zag form
    static void printZigZag(int row, int col, int a[][])
    {
        int evenRow = 0; // starts from the first row
        int oddRow = 1; // starts from the next row

        while (evenRow < row)
        {
            for (int i = 0; i < col; i++)
            {
                // evenRow will be printed in the same direction
                System.out.print(a[evenRow][i] + " ");
            }

            // Skipping next row so as to get the next evenRow
            evenRow = evenRow + 2;

            if(oddRow < row)
            {
            for (int i = col - 1; i >= 0; i--)
            {
                // oddRow will be printed in the opposite direction
                System.out.print(a[oddRow][i] + " ");
            }
            }

            // Skipping next row so as to get the next oddRow
            oddRow = oddRow + 2;
        }
    }

    public static void main(String[] args)
    {

        int r = 3, c = 5;

        int mat[][] = { {1, 2, 3, 4, 5},
                         {6, 7, 8, 9, 10},
                         {11, 12, 13, 14, 15}};

        printZigZag(r , c , mat);
    }
}

Python3

# Python 3 program to print
# matrix in zig-zag form

# Method to print matrix
# in zig-zag form
def printZigZag(row, col, a):
    evenRow = 0 # starts from the first row
    oddRow = 1 # starts from the next row

    while evenRow < row:
        for i in range(col):

            # evenRow will be printed
            # in the same direction
            print(str(a[evenRow][i] ),
                           end = " ")

        # Skipping next row so as
        # to get the next evenRow
        evenRow = evenRow + 2

        if oddRow < row:
            for i in range(col - 1, -1, -1):

                # oddRow will be printed in
                # the opposite direction
                print(str(a[oddRow][i]),
                             end = " ")

        # Skipping next row so as
        # to get the next oddRow
        oddRow = oddRow + 2

# Driver Code
r = 3
c = 5

mat = [[1, 2, 3, 4, 5],
       [6, 7, 8, 9, 10],
       [11, 12, 13, 14, 15]];

printZigZag(r , c , mat)

# This code is contributed
# by ChitraNayal

C#

// C# program to print matrix in zig-zag form
using System;

public class GFG {

    // Method to print matrix in zig-zag form
    static void printZigZag(int row, int col, int[, ] a)
    {

        // starts from the first row
        int evenRow = 0;

        // starts from the next row
        int oddRow = 1;

        while (evenRow < row) {
            for (int i = 0; i < col; i++) {

                // evenRow will be printed in
                // the same direction
                Console.Write(a[evenRow, i] + " ");
            }

            // Skipping next row so as to get the
            // next evenRow
            evenRow = evenRow + 2;

            if(oddRow < row)
            {
                for (int i = col - 1; i >= 0; i--)
                {

                    // oddRow will be printed in the
                    // opposite direction
                    Console.Write(a[oddRow, i] + " ");
                }
            }

            // Skipping next row so as to get
            // the next oddRow
            oddRow = oddRow + 2;
        }
    }

    public static void Main()
    {

        int r = 3, c = 5;

        int[, ] mat = { { 1, 2, 3, 4, 5 },
                        { 6, 7, 8, 9, 10 },
                        { 11, 12, 13, 14, 15 }
                      };

        printZigZag(r, c, mat);
    }
}

// This code is contributed by vt_m.

PHP

<?php
// PHP program to print
// matrix in zig-zag form

// Method to print matrix
// in zig-zag form
function printZigZag($row, $col, $a)
    {
        //starts from the first row
        $evenRow = 0;

        //starts from the next row
        $oddRow = 1;

        while ($evenRow < $row)
        {
            for ( $i = 0; $i < $col; $i++)
            {
                // evenRow will be printed
                // in the same direction
                echo $a[$evenRow][$i], " ";
            }

            // Skipping next row so as
            // to get the next evenRow
            $evenRow = $evenRow + 2;

            if($oddRow < $row)
            {
                for ($i = $col - 1; $i >= 0; $i--)
                {
                // oddRow will be printed in
                // the opposite direction
                echo $a[$oddRow][$i], " ";
                }
            }

            // Skipping next row so as
            // to get the next oddRow
            $oddRow = $oddRow + 2;
        }
    }

// Driver Code
$r = 3; $c = 5;
$mat = array(array(1, 2, 3, 4, 5),
             array(6, 7, 8, 9, 10),
             array(11, 12, 13, 14, 15));

printZigZag($r , $c , $mat);

// This code is contributed by m_kit.
?>

Javascript

// Javascript program to print
// matrix in zig-zag form
var MAX = 100;

    // Method to print matrix in zig-zag form
    var printZigZag = function(row, col, a)
    {
        var evenRow = 0; //starts from the first row
        var oddRow = 1; //starts from the next row

        while (evenRow<row)
        {
            for (var i = 0; i < col; i++)
            {
                // evenRow will be printed
                        // in the same direction
                document.write(a[evenRow][i]+ " ");
            }

            // Skipping next row so as
            // to get the next evenRow
            evenRow = evenRow + 2;

            if(oddRow < row)
            {
                for (var i = col - 1; i >= 0; i--)
                {

                // oddRow will be printed in
                // the opposite direction
                console.log(a[oddRow][i]+" ");
                }
            }

            // Skipping next row so as
                // to get the next oddRow
            oddRow = oddRow + 2;
        }
    }

// Driver function
    var r = 3, c = 5;
    var mat = [ [1, 2, 3, 4, 5],
                        [6, 7, 8, 9, 10],
                        [11, 12, 13, 14, 15]];

    printZigZag(r , c , mat);

    // This code is contributed by Pushpesh Raj.

Output

1 2 3 4 5 10 9 8 7 6 11 12 13 14 15 

Time Complexity: Time complexity of the above solution is O(row*column). 

Space Complexity: O(1)