@@ -13,6 +13,7 @@ My solutions to LeetCode problems in Kotlin.
 | [42](https://leetcode.com/problems/trapping-rain-water/) | [Trapping Rain Water](src/main/kotlin/com/schmoczer/leetcode/_0042/TrappingRainWater.kt) | Hard |
 | [48](https://leetcode.com/problems/rotate-image/) | [Rotate Image](src/main/kotlin/com/schmoczer/leetcode/_0048/RotateImage.kt) | Medium |
 | [49](https://leetcode.com/problems/group-anagrams/) | [Group Anagrams](src/main/kotlin/com/schmoczer/leetcode/_0049/GroupAnagrams.kt) | Medium |
+| [54](https://leetcode.com/problems/spiral-matrix/) | [Spiral Matrix](src/main/kotlin/com/schmoczer/leetcode/_0054/SpiralMatrix.kt) | Medium |
 | [73](https://leetcode.com/problems/set-matrix-zeroes/) | [Set Matrix Zeroes](src/main/kotlin/com/schmoczer/leetcode/_0073/SetMatrixZeroes.kt) | Medium |
 | [125](https://leetcode.com/problems/valid-palindrome/) | [Valid Palindrome](src/main/kotlin/com/schmoczer/leetcode/_0125/ValidPalindrome.kt) | Easy |
 | [151](https://leetcode.com/problems/reverse-words-in-a-string/) | [Reverse Words in a String](src/main/kotlin/com/schmoczer/leetcode/_0151/ReverseWordsInString.kt) | Medium |

@@ -0,0 +1,22 @@
+# Spiral Matrix
+
+Given an `m x n` `matrix`, return all elements of the `matrix` in spiral order.
+
+Example 1:
+
+> Input: matrix = [[1,2,3],[4,5,6],[7,8,9]]
+>
+> Output: [1,2,3,6,9,8,7,4,5]
+
+Example 2:
+
+> Input: matrix = [[1,2,3,4],[5,6,7,8],[9,10,11,12]]
+>
+> Output: [1,2,3,4,8,12,11,10,9,5,6,7]
+
+Constraints:
+
+- `m == matrix.length`
+- `n == matrix[i].length`
+- `1 <= m, n <= 10`
+- `-100 <= matrix[i][j] <= 100`

@@ -0,0 +1,59 @@
+package com.schmoczer.leetcode._0054
+
+class SpiralMatrix {
+fun spiralOrder(matrix: Array<IntArray>): List<Int> {
+var leftBoundary = -1
+var upperBoundary = 0
+var rightBoundary = matrix.first().size
+var lowerBoundary = matrix.size
+val result = mutableListOf<Int>()
+
+fun moveLeft(row: Int, column: Int): Pair<Int, Int> {
+for (i in (leftBoundary + 1 until column + 1).reversed()) {
+result.add(matrix[row][i])
+}
+leftBoundary++
+return Pair(row, leftBoundary)
+}
+
+fun moveUp(row: Int, column: Int): Pair<Int, Int> {
+for (i in (upperBoundary + 1 until row + 1).reversed()) {
+result.add(matrix[i][column])
+}
+upperBoundary++
+return Pair(upperBoundary, column)
+}
+
+fun moveRight(row: Int, column: Int): Pair<Int, Int> {
+for (i in column until rightBoundary) {
+result.add(matrix[row][i])
+}
+rightBoundary--
+return Pair(row, rightBoundary)
+}
+
+fun moveDown(row: Int, column: Int): Pair<Int, Int> {
+for (i in row until lowerBoundary) {
+result.add(matrix[i][column])
+}
+lowerBoundary--
+return Pair(lowerBoundary, column)
+}
+
+var row = 0
+var column = 0
+while (true) {
+val afterRight = moveRight(row, column)
+if (leftBoundary >= rightBoundary || upperBoundary >= lowerBoundary) break
+val afterDown = moveDown(afterRight.first + 1, afterRight.second)
+if (leftBoundary >= rightBoundary || upperBoundary >= lowerBoundary) break
+val afterLeft = moveLeft(afterDown.first, afterDown.second - 1)
+if (leftBoundary >= rightBoundary || upperBoundary >= lowerBoundary) break
+val afterUp = moveUp(afterLeft.first - 1, afterLeft.second)
+if (leftBoundary >= rightBoundary || upperBoundary >= lowerBoundary) break
+row = afterUp.first
+column = afterUp.second + 1
+}
+return result
+}
+}

@@ -0,0 +1,30 @@
+package com.schmoczer.leetcode._0054
+
+import org.junit.jupiter.api.BeforeEach
+import kotlin.test.Test
+import kotlin.test.assertEquals
+
+class SpiralMatrixTest {
+private lateinit var sut: SpiralMatrix
+
+@BeforeEach
+fun setUp() {
+sut = SpiralMatrix()
+}
+
+@Test
+fun `spiral a 3x3 matrix`() {
+val input = arrayOf(intArrayOf(1, 2, 3), intArrayOf(4, 5, 6), intArrayOf(7, 8, 9))
+val exptected = listOf(1, 2, 3, 6, 9, 8, 7, 4, 5)
+
+assertEquals(exptected, sut.spiralOrder(input))
+}
+
+@Test
+fun `spiral a 4x4 matrix`() {
+val input = arrayOf(intArrayOf(1, 2, 3, 4), intArrayOf(5, 6, 7, 8), intArrayOf(9, 10, 11, 12))
+val expected = listOf(1, 2, 3, 4, 8, 12, 11, 10, 9, 5, 6, 7)
+
+assertEquals(expected, sut.spiralOrder(input))
+}
+}