Travesrse Matrix Diagonally in Java

A matrix will be in M x N format.So what we need to do is, get value of indexes from 0,0 to M,N. Itreate the two dimensional array in diagonally as follow

50 36 22 31 88 87 27 73 95

After diagonal traverse the output will be.

50 31 36 27 88 22 73 87 95

Consider the above output

50 31 36 27 88 22

• These elements start from left to right top
• Need to iterate for 0 to M-1 using for loop and display corresponding elements diagonally using a while loop.
• To find next element use for formula: M-1,N+1 in while loop

73 87 95

• These elements start from bottom to right top
• Need to Iterate form 1 to N-1 in for loop and display corresponding elements diagonally using a while loop.
• So to find next element use for formula, M-1,N+1 in while loop

      TraveseMatrixDiagonally.java  

public class TraveseMatrixDiagonally { private static final int M = 4; private static final int N = 4; public static void main(String[] args) { TraveseMatrixDiagonally app = new TraveseMatrixDiagonally(); int[][] matrix = app.createMatrix(); app.printMatrix(matrix); app.traverseDiagonally(matrix); } private void traverseDiagonally(int[][] matrix) { for (int i = 0; i <= M - 1; i++) { int X = i; // temp M int Y = 0; // temp N while (X >= 0 && Y <= N - 1) { System.out.print(matrix[X][Y] + " "); X = X - 1; Y = Y + 1; } System.out.println(" "); } for (int i = 1; i <= N - 1; i++) { int X = M - 1; int Y = i; while (X >= 0 && Y <= N - 1) { System.out.print(matrix[X][Y] + " "); X = X - 1; Y = Y + 1; } System.out.println(" "); } } private int[][] createMatrix() { int matrix[][] = new int[M][N]; for (int i = 0; i < M; i++) { for (int j = 0; j < N; j++) { matrix[i][j] = (int) ((Math.random() * (99 + 1 - 10)) + 10); } } return matrix; } private void printMatrix(int[][] matrix) { for (int i = 0; i < M; i++) { for (int j = 0; j < N; j++) { System.out.print(matrix[i][j]); System.out.print(" "); } System.out.println(" "); } } } /* ****** SAMPLE INPUT ******** 61 44 88 74 44 32 86 56 92 ******* INPUT ******** ****** SAMPLE OUTPUT ******** 61 74 44 86 44 88 56 32 92 ******* OUTPUT ******** */

Reference Link https://www.youtube.com/watch?v=T8ErAYobcbc

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Traverse the matrix as spiral in Java

A matrix will be in M x N format.So what we need to do is, get value of indexes from 0,0 to m,n. Itreate the two dimensional array in spiral mode as follow

• we need to traverse matrix and remove the row/column which already traversed.
• We are not going to delete the elements instead we will limit it by defining boundaries. 
• Boundaries can be t, b, l, r we need to specify the direction variable dir. It decides the direction of traverse as below.
dir=0; ->right, dir=1 -> down, dir=2 -> left, dir=3 ->up

      TraverseMatrixSpiral.java  

package com.sk.iwq.matrix; public class TraverseMatrixSpiral { private static final int M = 3; private static final int N = 3; public static void main(String[] args) { TraverseMatrixSpiral app = new TraverseMatrixSpiral(); int matrix[][] = app.createMatrix(); app.printMatrix(matrix); System.out.println(app.traverseSpriral(matrix).toString()); } private StringBuilder traverseSpriral(int[][] matrix) { StringBuilder sb = new StringBuilder(); int dir = 0; int t = 0; int b = M - 1; int l = 0; int r = N - 1; while (t <= b && l <= r) { if (dir == 0) { for (int i = l; i <= r; i++) { sb.append(matrix[t][i] + ", "); } t++; } if (dir == 1) { for (int i = t; i <= b; i++) { sb.append(matrix[i][r] + ", "); } r--; } if (dir == 2) { for (int i = r; i >= l; i--) { sb.append(matrix[b][i] + ", "); } b--; } if (dir == 3) { for (int i = b; i <= t; i++) { sb.append(matrix[i][l] + ", "); } l++; } dir = (dir + 1) % 4; } return sb; } private int[][] createMatrix() { int matrix[][] = new int[M][N]; for (int i = 0; i < M; i++) { for (int j = 0; j < N; j++) { matrix[i][j] = (int) (Math.random() * 100 + 1); } } return matrix; } private void printMatrix(int[][] matrix) { for (int i = 0; i < M; i++) { for (int j = 0; j < N; j++) { System.out.print(matrix[i][j]); System.out.print(" "); } System.out.println(" "); } } } /* ****** SAMPLE INPUT ******** 50 36 22 31 88 87 27 73 95 ******* INPUT ******** ****** SAMPLE OUTPUT ******** 50, 36, 22, 87, 95, 73, 27, 31, 88 ******* OUTPUT ******** */

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Traverse the matrix in Java

Traverse the matrix in Java

• A matrix will be in M x N format.
• So what we need to do is, get value of indexes from 0,0 to m,n. 
•  Itreate the two dimensional array as follow

take 0(i) and traverse j till j < N
take 1(i) and traverse j till j < N
           .
           .
till M(i) and traverse j till j < N

      PrimeNumberCheck.java  

public class TraverseMatrix { private static final int M = 3; private static final int N = 3; public static void main(String[] args) { TraverseMatrix app = new TraverseMatrix(); int matrix[][] = app.createMatrix(); app.printMatrix(matrix); app.normalTraverse(matrix); } private void normalTraverse(int[][] matrix) { for (int i = 0; i < M; i++) { for (int j = 0; j < N; j++) { System.out.print(matrix[i][j]); System.out.print(", "); } } } private int[][] createMatrix() { int matrix[][] = new int[M][N]; for (int i = 0; i < M; i++) { for (int j = 0; j < N; j++) { matrix[i][j] = (int) (Math.random() * 100 + 1); } } return matrix; } private void printMatrix(int[][] matrix) { for (int i = 0; i < M; i++) { for (int j = 0; j < N; j++) { System.out.print(matrix[i][j]); System.out.print(" "); } System.out.println(" "); } } }

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