From 329cc3bcf9bc7d43c358f5d7e635a7d9db99890a Mon Sep 17 00:00:00 2001 From: Aman <84791435+Aman28801@users.noreply.github.com> Date: Tue, 3 Oct 2023 22:12:56 +0530 Subject: [PATCH] Added MirrorOfMatrix.java (#4461) * Added MirrorOfMatrix.java * Fixing Linting Issue * Fixing Linting Issue * Fixing Linting Issue * Fixing Linting Issue * Fixing Linting Issue * Fixing Linting Issue * Fixing Linting Issue * Fixing Linting Issue * Changes Done * Update src/main/java/com/thealgorithms/misc/MirrorOfMatrix.java Co-authored-by: Piotr Idzik <65706193+vil02@users.noreply.github.com> * Changes Done * Added MirrorOfMatrixTest.java * Added MirrorOfMatrixTest.java * Linting Error in Test * Linting Error in Test * Linting Error in Test * trying to fix build error * trying to fix build error * final * Update src/main/java/com/thealgorithms/misc/MirrorOfMatrix.java Co-authored-by: Piotr Idzik <65706193+vil02@users.noreply.github.com> * Update src/main/java/com/thealgorithms/misc/MirrorOfMatrix.java Co-authored-by: Piotr Idzik <65706193+vil02@users.noreply.github.com> * Update src/main/java/com/thealgorithms/misc/MirrorOfMatrix.java Co-authored-by: Piotr Idzik <65706193+vil02@users.noreply.github.com> * Update src/test/java/com/thealgorithms/misc/MirrorOfMatrixTest.java Co-authored-by: Piotr Idzik <65706193+vil02@users.noreply.github.com> * Update src/test/java/com/thealgorithms/misc/MirrorOfMatrixTest.java Co-authored-by: Piotr Idzik <65706193+vil02@users.noreply.github.com> * Update src/test/java/com/thealgorithms/misc/MirrorOfMatrixTest.java Co-authored-by: Piotr Idzik <65706193+vil02@users.noreply.github.com> * Changing Description * Final * Update src/main/java/com/thealgorithms/misc/MirrorOfMatrix.java Co-authored-by: Piotr Idzik <65706193+vil02@users.noreply.github.com> * Final * Update src/main/java/com/thealgorithms/misc/MirrorOfMatrix.java Co-authored-by: Piotr Idzik <65706193+vil02@users.noreply.github.com> * Changes * Changes * Linting Issue * Linting Issue * Linting Issue * Changes * Fixing Minor Linting Issue * Fixing Minor Linting Issue * Final * Update src/main/java/com/thealgorithms/misc/MirrorOfMatrix.java Co-authored-by: Piotr Idzik <65706193+vil02@users.noreply.github.com> * Changes * Linting Issue * Linting Issue * Linting Issue * Linting Issue * Update src/main/java/com/thealgorithms/misc/MirrorOfMatrix.java Co-authored-by: Piotr Idzik <65706193+vil02@users.noreply.github.com> * Update src/main/java/com/thealgorithms/misc/MirrorOfMatrix.java Co-authored-by: Piotr Idzik <65706193+vil02@users.noreply.github.com> * Update src/main/java/com/thealgorithms/misc/MirrorOfMatrix.java Co-authored-by: Piotr Idzik <65706193+vil02@users.noreply.github.com> * Changes * Changes * fix: use proper size in `checkInput` * style: basic linting --------- Co-authored-by: Piotr Idzik <65706193+vil02@users.noreply.github.com> Co-authored-by: vil02 --- .../thealgorithms/misc/MirrorOfMatrix.java | 57 +++++++++++++++++++ .../misc/MirrorOfMatrixTest.java | 53 +++++++++++++++++ 2 files changed, 110 insertions(+) create mode 100644 src/main/java/com/thealgorithms/misc/MirrorOfMatrix.java create mode 100644 src/test/java/com/thealgorithms/misc/MirrorOfMatrixTest.java diff --git a/src/main/java/com/thealgorithms/misc/MirrorOfMatrix.java b/src/main/java/com/thealgorithms/misc/MirrorOfMatrix.java new file mode 100644 index 00000000..89dfce3f --- /dev/null +++ b/src/main/java/com/thealgorithms/misc/MirrorOfMatrix.java @@ -0,0 +1,57 @@ +package com.thealgorithms.misc; + +// Problem Statement +/* +We have given an array of m x n (where m is the number of rows and n is the number of columns). +Print the new matrix in such a way that the new matrix is the mirror image of the original matrix. + +The Original matrix is: | The Mirror matrix is: +1 2 3 | 3 2 1 +4 5 6 | 6 5 4 +7 8 9 | 9 8 7 + +@author - Aman (https://github.com/Aman28801) +*/ + +public final class MirrorOfMatrix { + private MirrorOfMatrix() { + } + + public static int[][] mirrorMatrix(final int[][] originalMatrix) { + if (originalMatrix == null) { + // Handle invalid input + return null; + } + if (originalMatrix.length == 0) { + return new int[0][0]; + } + + checkInput(originalMatrix); + + int numRows = originalMatrix.length; + int numCols = originalMatrix[0].length; + + int[][] mirroredMatrix = new int[numRows][numCols]; + + for (int i = 0; i < numRows; i++) { + mirroredMatrix[i] = reverseRow(originalMatrix[i]); + } + return mirroredMatrix; + } + private static int[] reverseRow(final int[] inRow) { + int[] res = new int[inRow.length]; + for (int i = 0; i < inRow.length; ++i) { + res[i] = inRow[inRow.length - 1 - i]; + } + return res; + } + + private static void checkInput(final int[][] matrix) { + // Check if all rows have the same number of columns + for (int i = 1; i < matrix.length; i++) { + if (matrix[i].length != matrix[0].length) { + throw new IllegalArgumentException("The input is not a matrix."); + } + } + } +} diff --git a/src/test/java/com/thealgorithms/misc/MirrorOfMatrixTest.java b/src/test/java/com/thealgorithms/misc/MirrorOfMatrixTest.java new file mode 100644 index 00000000..0da0cf0f --- /dev/null +++ b/src/test/java/com/thealgorithms/misc/MirrorOfMatrixTest.java @@ -0,0 +1,53 @@ +package com.thealgorithms.misc; + +import static org.junit.jupiter.api.Assertions.assertArrayEquals; +import static org.junit.jupiter.api.Assertions.assertNull; +import static org.junit.jupiter.api.Assertions.assertThrows; + +import org.junit.jupiter.api.Test; + +class MirrorOfMatrixTest { + + @Test + void testMirrorMatrixRegularMatrix() { + int[][] originalMatrix = {{1, 2, 3}, {4, 5, 6}, {7, 8, 9}}; + int[][] expectedMirrorMatrix = {{3, 2, 1}, {6, 5, 4}, {9, 8, 7}}; + int[][] mirroredMatrix = MirrorOfMatrix.mirrorMatrix(originalMatrix); + assertArrayEquals(expectedMirrorMatrix, mirroredMatrix); + } + + @Test + void testMirrorMatrixEmptyMatrix() { + int[][] originalMatrix = {}; + int[][] expectedMirrorMatrix = {}; + int[][] mirroredMatrix = MirrorOfMatrix.mirrorMatrix(originalMatrix); + assertArrayEquals(expectedMirrorMatrix, mirroredMatrix); + } + + @Test + void testMirrorMatrixSingleElementMatrix() { + int[][] originalMatrix = {{42}}; + int[][] expectedMirrorMatrix = {{42}}; + int[][] mirroredMatrix = MirrorOfMatrix.mirrorMatrix(originalMatrix); + assertArrayEquals(expectedMirrorMatrix, mirroredMatrix); + } + + @Test + void testMirrorMatrixMultipleRowsOneColumnMatrix() { + int[][] originalMatrix = {{1}, {2}, {3}, {4}}; + int[][] expectedMirrorMatrix = {{1}, {2}, {3}, {4}}; + int[][] mirroredMatrix = MirrorOfMatrix.mirrorMatrix(originalMatrix); + assertArrayEquals(expectedMirrorMatrix, mirroredMatrix); + } + + @Test + void testMirrorMatrixNullInput() { + int[][] originalMatrix = null; + assertNull(MirrorOfMatrix.mirrorMatrix(originalMatrix)); + } + + @Test + void testMirrotMarixThrows() { + assertThrows(IllegalArgumentException.class, () -> MirrorOfMatrix.mirrorMatrix(new int[][] {{1}, {2, 3}})); + } +}