Java Program to Print Boundary Elements of the Matrix

Given a matrix of size Row x Col Print the boundary elements of the matrix. Boundary elements are those elements which are not surrounded by elements on all four directions, i.e. elements in the first row, first column, last row and last column.
Example:
Input :
         1 2 3
         4 5 6
         7 8 9
Output:  
        1 2 3
        4   6
        7 8 9
Approach:
- Take the matrix as input from the user of N × M dimension.
 - Print the border elements of the matrix using for loop.
 
Below is the implementation of the problem statement:
Java
// Java Program to Print Boundary// Elements of the Matrix  import java.util.*;  public class GFG {      public void Boundary_Elements(int mat[][])    {        // Printing Input Matrix;        System.out.println("Input Matrix is : ");          for (int i = 0; i < mat.length; i++) {            for (int j = 0; j < mat[i].length; j++) {                  System.out.print(mat[i][j]);            }              System.out.println();        }          // Printing Boundary Values of Matrix        System.out.println("Resultant Matrix is :");          for (int i = 0; i < mat.length; i++) {            for (int j = 0; j < mat[i].length; j++) {                  if (i == 0 || j == 0 || i == mat.length - 1                    || j == mat[i].length - 1) {                    System.out.print(mat[i][j]);                }                else {                    // Printing Space if element                    // is not at Boundary                    System.out.print(" ");                }            }              System.out.println();        }    }    public static void main(String[] args)    {        // Input Matrix        int mat[][] = new int[][] { { 1, 2, 3 },                                    { 4, 5, 6 },                                    { 7, 8, 9 } };          GFG B_Values = new GFG();          B_Values.Boundary_Elements(mat);    }} | 
Output
Input Matrix is : 123 456 789 Resultant Matrix is : 123 4 6 789
Time Complexity: O(N × M), where n and m are the dimensions of the matrix.
Space Complexity: O(N × M).
				
					


