From 14f5c1624c240ad4600f9bae6f00800d36ecb991 Mon Sep 17 00:00:00 2001
From: Robert Manigk <p1ng0ut@mailbox.org>
Date: Mon, 20 Feb 2023 19:33:57 +0100
Subject: [PATCH] Programming example sum of squares

---
 .../space.dezentrale.prgrnd/SumOfSquares.kt   |  8 ++++++++
 .../space.dezentrale.prgrnd/SumOfTwo.kt       |  4 ++--
 .../dezentrale/prgrnd/SumOfSquaresTest.kt     | 20 +++++++++++++++++++
 .../space/dezentrale/prgrnd/SumOfTwoTest.kt   | 12 +++++------
 4 files changed, 36 insertions(+), 8 deletions(-)
 create mode 100644 src/nativeMain/kotlin/space.dezentrale.prgrnd/SumOfSquares.kt
 create mode 100644 src/nativeTest/kotlin/space/dezentrale/prgrnd/SumOfSquaresTest.kt

diff --git a/src/nativeMain/kotlin/space.dezentrale.prgrnd/SumOfSquares.kt b/src/nativeMain/kotlin/space.dezentrale.prgrnd/SumOfSquares.kt
new file mode 100644
index 0000000..c208a98
--- /dev/null
+++ b/src/nativeMain/kotlin/space.dezentrale.prgrnd/SumOfSquares.kt
@@ -0,0 +1,8 @@
+package space.dezentrale.prgrnd
+
+class SumOfSquares {
+    fun calculate(intArray: IntArray): Int {
+
+        return intArray.sumOf { it * it }
+    }
+}
\ No newline at end of file
diff --git a/src/nativeMain/kotlin/space.dezentrale.prgrnd/SumOfTwo.kt b/src/nativeMain/kotlin/space.dezentrale.prgrnd/SumOfTwo.kt
index 4b8ddd8..d5142bf 100644
--- a/src/nativeMain/kotlin/space.dezentrale.prgrnd/SumOfTwo.kt
+++ b/src/nativeMain/kotlin/space.dezentrale.prgrnd/SumOfTwo.kt
@@ -13,12 +13,12 @@ class SumOfTwo {
     }
 
     fun optimalSolution(nums: IntArray, target: Int): IntArray {
-        val numsToIndices = nums.mapIndexed { index: Int, num: Int -> num to index }.toMap()
-        println("numsToIndices = $numsToIndices")
+        val numsToIndices = mutableMapOf<Int, Int>()
         for ((index, num) in nums.withIndex()) {
             if (numsToIndices.containsValue(target - num)) {
                 return intArrayOf(numsToIndices[target - num]!!, index)
             }
+            numsToIndices[target] = index
         }
         return intArrayOf(-1, -1)
     }
diff --git a/src/nativeTest/kotlin/space/dezentrale/prgrnd/SumOfSquaresTest.kt b/src/nativeTest/kotlin/space/dezentrale/prgrnd/SumOfSquaresTest.kt
new file mode 100644
index 0000000..6b332fe
--- /dev/null
+++ b/src/nativeTest/kotlin/space/dezentrale/prgrnd/SumOfSquaresTest.kt
@@ -0,0 +1,20 @@
+package space.dezentrale.prgrnd
+
+import kotlin.test.Test
+import kotlin.test.assertEquals
+
+class SumOfSquaresTest {
+    @Test
+    fun `it calculates sum of one`() {
+        val sumOfSquares = SumOfSquares()
+
+        assertEquals(4, sumOfSquares.calculate(intArrayOf(-2)))
+    }
+
+    @Test
+    fun `it calculates sum of two`() {
+        val sumOfSquares = SumOfSquares()
+
+        assertEquals(13, sumOfSquares.calculate(intArrayOf(-2, 3)))
+    }
+}
\ No newline at end of file
diff --git a/src/nativeTest/kotlin/space/dezentrale/prgrnd/SumOfTwoTest.kt b/src/nativeTest/kotlin/space/dezentrale/prgrnd/SumOfTwoTest.kt
index 875f483..4c19411 100644
--- a/src/nativeTest/kotlin/space/dezentrale/prgrnd/SumOfTwoTest.kt
+++ b/src/nativeTest/kotlin/space/dezentrale/prgrnd/SumOfTwoTest.kt
@@ -10,7 +10,7 @@ class SumOfTwoTest {
 
         val twoSum = sumOfTwo.simpleSolution(intArrayOf(2, 7, 11, 15), 9)
 
-        assertContentEquals(twoSum, intArrayOf(0, 1))
+        assertContentEquals(intArrayOf(0, 1), twoSum)
     }
 
     @Test
@@ -19,7 +19,7 @@ class SumOfTwoTest {
 
         val twoSum = sumOfTwo.simpleSolution(intArrayOf(3, 2, 4), 6)
 
-        assertContentEquals(twoSum, intArrayOf(1, 2))
+        assertContentEquals(intArrayOf(1, 2), twoSum)
     }
 
     @Test
@@ -28,7 +28,7 @@ class SumOfTwoTest {
 
         val twoSum = sumOfTwo.simpleSolution(intArrayOf(3, 3), 6)
 
-        assertContentEquals(twoSum, intArrayOf(0, 1))
+        assertContentEquals(intArrayOf(0, 1), twoSum)
     }
 
     @Test
@@ -37,7 +37,7 @@ class SumOfTwoTest {
 
         val twoSum = sumOfTwo.optimalSolution(intArrayOf(2, 7, 11, 15), 9)
 
-        assertContentEquals(twoSum, intArrayOf(0, 1))
+        assertContentEquals(intArrayOf(0, 1), twoSum)
     }
 
     @Test
@@ -46,7 +46,7 @@ class SumOfTwoTest {
 
         val twoSum = sumOfTwo.optimalSolution(intArrayOf(3, 2, 4), 6)
 
-        assertContentEquals(twoSum, intArrayOf(1, 2))
+        assertContentEquals(intArrayOf(1, 2), twoSum)
     }
 
     @Test
@@ -55,6 +55,6 @@ class SumOfTwoTest {
 
         val twoSum = sumOfTwo.optimalSolution(intArrayOf(3, 3), 6)
 
-        assertContentEquals(twoSum, intArrayOf(0, 1))
+        assertContentEquals(intArrayOf(0, 1), twoSum)
     }
 }
\ No newline at end of file