merge sort

go.mod

@@ -0,0 +1,3 @@
+module git.emaker.limited/chopster44/sorts
+
+go 1.27.1

main.go

@@ -0,0 +1,61 @@
+package main
+
+import (
+	"fmt"
+)
+
+var inputData []int = []int{5, 6, 1, 15, 80, 89, 12, 20, 10, 28}
+
+func mergeSort(array []int) []int {
+	if len(array) > 1 {
+		fmt.Printf("splitting %x ", array)
+		var halfArray int = int(len(array) / 2)
+		left := array[:halfArray]
+		right := array[halfArray:]
+		fmt.Printf("to %x %x, halfArray=%x\n", left, right, halfArray)
+		left = mergeSort(left)
+		right = mergeSort(right)
+		fmt.Printf("merging %x and %x { ", left, right)
+
+		out := make([]int, 0, len(left)+len(right))
+
+		lp, rp := 0, 0
+
+		for lp < len(left) && rp < len(right) {
+			fmt.Printf("comparing left[%x]=%x and right[%x]=%x, ", lp, left[lp], rp, right[rp])
+			if left[lp] == right[rp] {
+				out = append(out, right[rp])
+				out = append(out, left[lp])
+				lp++
+				rp++
+			} else if left[lp] > right[rp] {
+				out = append(out, right[rp])
+				rp++
+			} else {
+				out = append(out, left[lp])
+				lp++
+			}
+		}
+
+		for lp < len(left) {
+			fmt.Printf("%x remaining in left, ", lp)
+			out = append(out, left[lp])
+			lp++
+		}
+
+		for rp < len(right) {
+			fmt.Printf("%x remaining in right, ", rp)
+			out = append(out, right[rp])
+			rp++
+		}
+		fmt.Printf("} to %x\n", out)
+		return out
+	} else {
+		return array
+	}
+}
+
+func main() {
+	fmt.Printf("sorting %x \n", inputData)
+	fmt.Printf("sorted %x\n", mergeSort(inputData))
+}