Interchange elements of first and last rows in matrix
Given a 4 x 4 matrix, we have to interchange the elements of first and last row and show the resulting matrix.
Examples :
Input : 3 4 5 0 2 6 1 2 2 7 1 2 2 1 1 2 Output : 2 1 1 2 2 6 1 2 2 7 1 2 3 4 5 0 Input : 9 7 5 1 2 3 4 1 5 6 6 5 1 2 3 1 Output : 1 2 3 1 2 3 4 1 5 6 6 5 9 7 5 1
The approach is very simple, we can simply swap the elements of first and last row of the matrix inorder to get the desired matrix as output.
Below is the implementation of the approach :
C++
// C++ code to swap the element of first // and last row and display the result #include <iostream> using namespace std; #define n 4 void interchangeFirstLast( int m[][n]) { int rows = n; // swapping of element between first // and last rows for ( int i = 0; i < n; i++) { int t = m[0][i]; m[0][i] = m[rows - 1][i]; m[rows - 1][i] = t; } } // Driver function int main() { // input in the array int m[n][n] = { { 8, 9, 7, 6 }, { 4, 7, 6, 5 }, { 3, 2, 1, 8 }, { 9, 9, 7, 7 } }; interchangeFirstLast(m); // printing the interchanged matrix for ( int i = 0; i < n; i++) { for ( int j = 0; j < n; j++) cout << m[i][j] << " " ; cout << endl; } } // This code is contributed by Anant Agarwal. |
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Java
// Java code to swap the element of first // and last row and display the result import java.io.*; public class Interchange { static void interchangeFirstLast( int m[][]) { int rows = m.length; // swapping of element between first // and last rows for ( int i = 0 ; i < m[ 0 ].length; i++) { int t = m[ 0 ][i]; m[ 0 ][i] = m[rows- 1 ][i]; m[rows- 1 ][i] = t; } } // Driver code public static void main(String args[]) throws IOException { // input in the array int m[][] = { { 8 , 9 , 7 , 6 }, { 4 , 7 , 6 , 5 }, { 3 , 2 , 1 , 8 }, { 9 , 9 , 7 , 7 } }; interchangeFirstLast(m); // printing the interchanged matrix for ( int i = 0 ; i < m.length; i++) { for ( int j = 0 ; j < m[ 0 ].length; j++) System.out.print(m[i][j] + " " ); System.out.println(); } } } |
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Python3
# Python code to swap the element # of first and last row and display # the result def interchangeFirstLast(mat, n, m): rows = n # swapping of element between # first and last rows for i in range (n): t = mat[ 0 ][i] mat[ 0 ][i] = mat[rows - 1 ][i] mat[rows - 1 ][i] = t # Driver Program mat = [[ 8 , 9 , 7 , 6 ], [ 4 , 7 , 6 , 5 ], [ 3 , 2 , 1 , 8 ], [ 9 , 9 , 7 , 7 ]] n = 4 m = 4 interchangeFirstLast(mat, n, m) # printing the interchanged matrix for i in range (n): for j in range (m): print (mat[i][j], end = " " ) print ( "\n" ) # This code is contributed by Shrikant13. |
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C#
// C# code to swap the element of first // and last row and display the result using System; class GFG { public static void interchangeFirstLast( int [][] m) { int rows = m.Length; // swapping of element between first // and last rows for ( int i = 0; i < m[0].Length; i++) { int t = m[0][i]; m[0][i] = m[rows - 1][i]; m[rows - 1][i] = t; } } // Driver code public static void Main( string [] args) { // input in the array int [][] m = new int [][] { new int [] {8, 9, 7, 6}, new int [] {4, 7, 6, 5}, new int [] {3, 2, 1, 8}, new int [] {9, 9, 7, 7} }; interchangeFirstLast(m); // printing the interchanged matrix for ( int i = 0; i < m.Length; i++) { for ( int j = 0; j < m[0].Length; j++) { Console.Write(m[i][j] + " " ); } Console.WriteLine(); } } } // This code is contributed by Shrikant13 |
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PHP
<?php // PHP code to swap the element of first // and last row and display the result $n = 4; function interchangeFirstLast(& $m ) { global $n ; $rows = $n ; // swapping of element between first // and last rows for ( $i = 0; $i < $n ; $i ++) { $t = $m [0][ $i ]; $m [0][ $i ] = $m [ $rows - 1][ $i ]; $m [ $rows - 1][ $i ] = $t ; } } // Driver function // input in the array $m = array ( array (8, 9, 7, 6), array (4, 7, 6, 5), array ( 3, 2, 1, 8), array (9, 9, 7, 7)); interchangeFirstLast( $m ); // printing the interchanged matrix for ( $i = 0; $i < $n ; $i ++) { for ( $j = 0; $j < $n ; $j ++) echo $m [ $i ][ $j ] . " " ; echo "\n" ; } ?> |
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Output :
9 9 7 7 4 7 6 5 3 2 1 8 8 9 7 6
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