Program to print elements of a Matrix row-wise skipping alternate elements - GeeksforGeeks

27 Oct, 2021
Given a matrix of N*N size where N is always odd, the task is to print elements of a matrix row-wise skipping alternate elements.Examples:  
Input: mat[3][3] = 
{{1, 4, 3},
 {2, 5, 6},
 {7, 8, 9}}
Output: 1 3 5 7 9

Input: mat[5][5] = 
{{1, 2, 3, 4, 9},
 {5, 6, 7, 8, 44},
 {19, 10, 11, 12, 33},
 {13, 14, 15, 16, 55},
 {77, 88, 99, 111, 444}}
Output: 1 3 9 6 8 19 11 33 14 16 77 99 444 
 
Approach:  
Start traversing the matrix.For each row, check if the row number is even or odd. If the row is even, then print the elements at the even index of that row.If the row is odd, print the elements at the odd index of that row.
Start traversing the matrix.
For each row, check if the row number is even or odd. If the row is even, then print the elements at the even index of that row.If the row is odd, print the elements at the odd index of that row.
If the row is even, then print the elements at the even index of that row.
If the row is odd, print the elements at the odd index of that row.
Below is the implementation of above approach:  
C++
Java
Python3
C#
PHP
Javascript
// C++ program to print elements of a Matrix// row-wise skipping alternate elements#include <bits/stdc++.h>using namespace std;#define R 100#define C 100 // Function to print the alternate// elements of a matrixvoid printElements(int mat[][C], int n){    for (int i = 0; i < n; i++) {        if (i % 2 == 0)            for (int j = 0; j < n; j += 2)                cout << mat[i][j] << " ";        else            for (int j = 1; j < n; j += 2)                cout << mat[i][j] << " ";    }} // Driver codeint main(){    int n = 3;    int mat[R][C] = { { 1, 5, 3 },                      { 2, 4, 7 },                      { 9, 8, 6 } };     printElements(mat, n);     return 0;}
// Java Program to print elements of a Matrix// row-wise skipping alternate elementsimport java.util.*;import java.lang.*; class GFG{// Function to print the alternate// elements of a matrixstatic void printElements(int[][] mat, int n){    for (int i = 0; i < n; i++)    {        if (i % 2 == 0)            for (int j = 0; j < n; j += 2)                System.out.print(mat[i][j] + " ");        else            for (int j = 1; j < n; j += 2)                System.out.print(mat[i][j] + " ");    }} // Driver codepublic static void main(String args[]){    int n = 3;    int[][] mat = new int[][]{ { 1, 5, 3 },{ 2, 4, 7 },{ 9, 8, 6 } };     printElements(mat, n);}} // This code is contributed// by Akanksha Rai(Abby_akku)
# Python 3 program to print elements of a Matrix# row-wise skipping alternate elements  # Function to print the alternate# elements of a matrixdef printElements(mat, n) :     for i in range(n) :        if i % 2 == 0 :            for j in range(0, n, 2) :                print(mat[i][j],end = " ")        else :            for j in range(1, n, 2) :                print(mat[i][j],end =" ")                  # Driver Codeif __name__ == "__main__" :     n = 3    mat = [ [ 1, 5, 3],            [ 2, 4, 7],            [ 9, 8, 6] ]     printElements(mat , n)  # This code is contributed by ANKITRAI1
// C# Program to print elements// of a Matrix row-wise skipping// alternate elementsusing System; class GFG{// Function to print the alternate// elements of a matrixstatic void printElements(int[,] mat,                          int n){    for (int i = 0; i < n; i++)    {        if (i % 2 == 0)            for (int j = 0; j < n; j += 2)                Console.Write(mat[i, j] + " ");        else            for (int j = 1; j < n; j += 2)                Console.Write(mat[i, j] + " ");    }} // Driver codepublic static void Main(){    int n = 3;    int[,] mat = new int[,]{ { 1, 5, 3 },                             { 2, 4, 7 },                             { 9, 8, 6 }};     printElements(mat, n);}} // This code is contributed// by ChitraNayal
<?php// PHP program to print elements of a Matrix// row-wise skipping alternate elements // Function to print the alternate// elements of a matrixfunction printElements(&$mat, $n){    for ($i = 0; $i < $n; $i++)    {        if ($i % 2 == 0)            for ($j = 0; $j < $n; $j += 2)            {                echo $mat[$i][$j] ;                echo " ";            }        else            for ($j = 1; $j < $n; $j += 2)            {                echo $mat[$i][$j] ;                echo " ";            }    }} // Driver code$n = 3;$arr = array(array(1, 2, 4),             array(5, 6, 8));$mat = array(array(1, 5, 3),             array(2, 4, 7),             array(9, 8, 6)); printElements($mat, $n); // This code is contributed// by Shivi_Aggarwal?>
<script>// javascript Program to print elements of a Matrix// row-wise skipping alternate elements     // Function to print the alternate    // elements of a matrix    function printElements(mat , n) {        for (i = 0; i < n; i++) {            if (i % 2 == 0)                for (j = 0; j < n; j += 2)                    document.write(mat[i][j] + " ");            else                for (j = 1; j < n; j += 2)                    document.write(mat[i][j] + " ");        }    }     // Driver code             var n = 3;        var mat =[[ 1, 5, 3 ],        [2, 4, 7 ], [        9, 8, 6 ] ];         printElements(mat, n); // This code contributed by umadevi9616</script>
1 3 4 9 6
 
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