cleanup and tangle sample file

Author: togakangaroo

spiral-matrix-path/README.md

@@ -1,5 +1,7 @@
 This is [this leetcode problem](https://leetcode.com/problems/spiral-matrix-iii/description/) from [Underdog Devs](https://underdog-devs.slack.com/archives/C02FFHZT200/p1723032739134259)
 
+[Go to tangled solution file](./matrix-spiral-order.kts)
+
 
 # Problem Statement
 

spiral-matrix-path/README.org

@@ -3,6 +3,8 @@
 
 This is [[https://leetcode.com/problems/spiral-matrix-iii/description/][this leetcode problem]] from [[https://underdog-devs.slack.com/archives/C02FFHZT200/p1723032739134259][Underdog Devs]]
 
+[[./matrix-spiral-order.kts][Go to tangled solution file]]
+
 * Problem Statement
 You start at the cell ~(rStart, cStart)~ of an rows x cols grid facing east. The northwest corner is at the first row and column in the grid, and the southeast corner is at the last row and column.
 
@@ -269,8 +271,7 @@ That's right, what if we started in column 2?
 : res3: kotlin.String = >>> 
 
 Oh that's cool. And the right answer. Lets see it with Example 2
-
-#+begin_src kotlin
+#+begin_src kotlin :tangle matrix-spiral-order.kts
   var rows = 5
   var columns = 6
   var rStart = 1

spiral-matrix-path/matrix-spiral-order.kts

@@ -0,0 +1,38 @@
+var rows = 5
+var columns = 6
+var rStart = 1
+var cStart = 4
+data class Coordinates(val row: Int, val column: Int)
+
+
+fun spiral(): Sequence<Coordinates> = sequence {
+    var row = 0
+    var col = 0
+
+    yield(Coordinates(row, col))
+
+    val ordinals = generateSequence(1) { it + 1}
+    val sideSizes = ordinals.iterator()
+
+    while (true) {
+        var sideSize = sideSizes.next()
+        // →
+        for (n in 0 until sideSize)
+            yield(Coordinates(row, ++col))
+        // ↓
+        for (n in 0 until sideSize)
+            yield(Coordinates(++row, col))
+
+        var nextSideSize = sideSizes.next()
+        // ←
+        for (n in 0 until nextSideSize)
+            yield(Coordinates(row, --col))
+        // ↑
+        for (n in 0 until nextSideSize)
+            yield(Coordinates(--row, col))
+    }
+}
+var spiralCoordinates = spiral().map{ Coordinates(it.row+rStart, it.column+cStart)}
+var onGridSpiral = spiralCoordinates.filter { it.row in 0..(rows-1) && it.column in 0..(columns-1) }
+var gridInSpiralOrder = onGridSpiral.take(rows*columns)
+"\n"+gridInSpiralOrder.map{ "[${it.row}, ${it.column}]"}.joinToString("\n")