added Mergesort for kotlin

Author: slvignesh05

README.md

@@ -3159,6 +3159,11 @@ In order to achieve greater coverage and encourage more people to contribute to
                     <img align="center" height="25" src="./logos/java.svg" />
                 </a>
             </td>
+            <td> <!-- kotlin -->
+                <a href="./src/kotlin/MergeSort.kt">
+                    <img align="center" height="25" src="./logos/kotlin.svg" />
+                </a>
+            </td>
             <td> <!-- Python -->
                 <a href="./src/python/merge_sort.py">
                     <img align="center" height="25" src="./logos/python.svg" />

src/kotlin/MergeSort.kt

@@ -0,0 +1,49 @@
+fun mergeSort(arr: IntArray): IntArray {
+    if (arr.size <= 1) {
+        return arr
+    }
+
+    val middle = arr.size / 2
+    val left = arr.copyOfRange(0, middle)
+    val right = arr.copyOfRange(middle, arr.size)
+
+    return merge(mergeSort(left), mergeSort(right))
+}
+
+fun merge(left: IntArray, right: IntArray): IntArray {
+    var result = IntArray(left.size + right.size)
+    var leftIndex = 0
+    var rightIndex = 0
+    var resultIndex = 0
+
+    while (leftIndex < left.size && rightIndex < right.size) {
+        if (left[leftIndex] < right[rightIndex]) {
+            result[resultIndex] = left[leftIndex]
+            leftIndex++
+        } else {
+            result[resultIndex] = right[rightIndex]
+            rightIndex++
+        }
+        resultIndex++
+    }
+
+    while (leftIndex < left.size) {
+        result[resultIndex] = left[leftIndex]
+        leftIndex++
+        resultIndex++
+    }
+
+    while (rightIndex < right.size) {
+        result[resultIndex] = right[rightIndex]
+        rightIndex++
+        resultIndex++
+    }
+
+    return result
+}
+
+fun main() {
+    val arr = intArrayOf(12, 11, 13, 5, 6, 7)
+    val sortedArray = mergeSort(arr)
+    println("Sorted array: ${sortedArray.joinToString(", ")}")
+}