Added selection sort

Author: igorwojda

README.md

@@ -22,19 +22,17 @@ by checking out this the project from git repository.
    ice preview of markdown files (files containing puzzles description)
 
 ## Puzzle structure
-Each puzzle is located in separate package and it contains 3 files
-([screen](./misc/images/SampleTask.png)):
+Each puzzle is located in separate package and it contains 3 files ([screen](./misc/image/SampleTask.png)):
 * `Puzzle.md` - description of the puzzle
 * `Puzzle.kt` - contains empty method/class where puzzle should be solved and set of tests to run
 * `PuzzleSolution.kt - file that contains one or more puzzle solutions (encapsulated in Kotlin `object` just to avoid conflicts with
   other coding puzzles)
 
 ## Running tests
 
-Open `Puzzle.kt` file for a any puzzle. Locate class with `Test` suffix (`PuzzleTest`). Click on the green green arrow close to line
-number to run one or more tests in the class
-([screen](./misc/images/RunTest.png)). After running the test you can rerun last
-configuration using `Run command` (`⌘ + R`).
+Open `Puzzle.kt` file for a any puzzle. Locate class with `Test` suffix (`PuzzleTest`). Click on the green green arrow close to line number
+to run one or more tests in the class ([screen](./misc/image/RunTest.png)). After running the test you can rerun last configuration using
+`Run command` (`⌘ + R`).
 
 Larger puzzles will have larger test base, so tests have to be uncommented one by one while solving various steps of the given puzzle.
 
@@ -65,6 +63,7 @@ same tasks multiple times be patient and persistent over time.
 **List**
 * [List chunking](app/src/test/java/com/igorwojda/codingpuzzle/listchunk/ListChunk.md)
 * [Bubble sort](app/src/test/java/com/igorwojda/datastructure/list/bubblesort/BubbleSort.md)
+* [Selection sort](app/src/test/java/com/igorwojda/datastructure/list/selectionsort/SelectionSort.md)
 
 **Queue**
 * [Int queue](app/src/test/java/com/igorwojda/datastructure/queue/int/IntQueue.md)
@@ -127,6 +126,6 @@ If you think something is incorrect, you have found a new puzzle, have a better
 please create PR or open a new issue.
 
 # Follow me
-![avatar.png](misc/images/avatar.png)
+![avatar.png](misc/image/avatar.png)
 
 [Twitter](https://twitter.com/igorwojda) | [Medium](https://medium.com/@igorwojda) | [Linkedin](https://www.linkedin.com/in/igorwojda/)

app/src/test/java/com/igorwojda/datastructure/list/bubblesort/BubbleSort.md

@@ -6,6 +6,7 @@
 
 Sort list of numbers from lowest number to greatest number using [bubble sort](https://en.wikipedia.org/wiki/Bubble_sort).
 
+Algorithm:
 Starting from the beginning of the list, compare every adjacent pair, swap their position if they are not in the right order (the latter one
 is smaller than the former one). After each iteration, one less element (the last one) is needed to be compared until there are no more
 elements left to be compared.

app/src/test/java/com/igorwojda/datastructure/list/bubblesort/BubbleSortSolution.kt

@@ -4,7 +4,7 @@ private object BubbleSortSolution {
     private fun bubbleSort(list: List<Int>): List<Number> {
         val sorted = list.toMutableList()
 
-        sorted.forEachIndexed { i, _ ->
+        (0..sorted.lastIndex).forEach { i ->
             var swapped = false
             (0 until (sorted.size - i - 1)).forEach { j ->
                 val element = sorted[j]

app/src/test/java/com/igorwojda/datastructure/list/bubblesort/BubbleSort.kt renamed to app/src/test/java/com/igorwojda/datastructure/list/bubblesort/selectionSort.kt

@@ -3,7 +3,7 @@ package com.igorwojda.datastructure.list.bubblesort
 import org.amshove.kluent.shouldEqual
 import org.junit.Test
 
-private fun bubbleSort(list: List<Int>): List<Number> {
+private fun selectionSort(list: List<Int>): List<Number> {
     return list
 }
 
@@ -15,6 +15,6 @@ class BubbleSortTest {
 
     @Test
     fun `bubble sort test`() {
-        bubbleSort(LIST) shouldEqual SORTED_LIST
+        selectionSort(LIST) shouldEqual SORTED_LIST
     }
 }

app/src/test/java/com/igorwojda/datastructure/list/selectionsort/SelectionSort.kt

@@ -0,0 +1,20 @@
+package com.igorwojda.datastructure.list.selectionsort
+
+import org.amshove.kluent.shouldEqual
+import org.junit.Test
+
+private fun selectionSort(list: List<Int>): List<Number> {
+    return list
+}
+
+class SelectionSortTest {
+    companion object {
+        val LIST = listOf(5, 1, 4, 2, 8)
+        val SORTED_LIST = listOf(1, 2, 4, 5, 8)
+    }
+
+    @Test
+    fun `selection sort test`() {
+        selectionSort(LIST) shouldEqual SORTED_LIST
+    }
+}

app/src/test/java/com/igorwojda/datastructure/list/selectionsort/SelectionSort.md

@@ -0,0 +1,28 @@
+# Selection sort
+
+## Instructions
+
+[Puzzle files](.)
+
+Sort list of numbers from lowest number to greatest number using [selection sort](https://en.wikipedia.org/wiki/Selection_sort).
+
+Algorithm: Sort an list by repeatedly finding the minimum element (ascending order) from unsorted part and putting it at the beginning of
+the list.
+
+## Examples
+
+Example 1
+
+Sort `[5, 1, 4, 2, 8]`
+
+
+
+## Hints
+
+<details>
+<summary>Hint 1</summary>
+The algorithm uses two sublists in a given array.
+
+1. The sublist which is already sorted
+2. Remaining sublist which is unsorted
+</details>

app/src/test/java/com/igorwojda/datastructure/list/selectionsort/SelectionSortSolution.kt

@@ -0,0 +1,25 @@
+package com.igorwojda.datastructure.list.bubblesort
+
+private object SelectionSortSolution {
+    private fun selectionSort(list: List<Int>): List<Number> {
+        val sorted = list.toMutableList()
+
+        (0..sorted.lastIndex).forEach { i ->
+            var indexOfMin = i
+
+            ((i + 1)..sorted.lastIndex).forEach { j ->
+                if(sorted[j] < sorted[indexOfMin]) {
+                    indexOfMin = j
+                }
+            }
+
+            if(indexOfMin != i) {
+                val temp = sorted[i]
+                sorted[i] = sorted[indexOfMin]
+                sorted[indexOfMin] = temp
+            }
+        }
+
+        return sorted
+    }
+}

app/src/test/java/com/igorwojda/datastructure/tree/traversal/TreeTraversal.md

@@ -17,7 +17,7 @@ using `Breath-First` and `Depth-First` traversals.
 
 Example:
 
-<img src="./misc/breadth_first_traversal.svg">
+![breadth_first_traversal.svg](misc/breadth_first_traversal.svg)
 
 ### 2. Depth First traversal (DF traversal)
 
@@ -26,5 +26,4 @@ Example:
 * **Test**: `depth first traverse`
 
 Example:
-
-<img src="./misc/depth_first_traversal.svg">
+![depth_first_traversal.svg](misc/depth_first_traversal.svg)