feat: add second solution for shuffle experiment

experiments/go/shuffle-elements/shuffle.go

@@ -7,10 +7,10 @@ const (
 	right
 )
 
-// shuffle creates a new list where an element in one position is repositioned
+// shuffleFuncOne creates a new list where an element in one position is repositioned
-// to the index of another element. All affected elements then shuffle one place to the left
+// to the index of another element. All affected elements then shuffleFuncOne one place to the left
 // or right depending on the direction of the move.
-func shuffle(list []any, oldPos, newPos int) []any {
+func shuffleFuncOne(list []any, oldPos, newPos int) []any {
 	var direction shuffleDirection
 
 	if newPos < oldPos {
@@ -40,3 +40,33 @@ func shuffle(list []any, oldPos, newPos int) []any {
 
 	return newList
 }
+
+// shuffleFuncTwo produces the same output as shuffleFuncOne using a slightly different method.
+// The original slice is copied into a new slice and the element is immediately placed in the new
+// position. The for loop then only focuses on the elements in range between the two positions and
+// are shuffled left or right as required.
+func shuffleFuncTwo(list []any, oldPos, newPos int) []any {
+	newList := make([]any, len(list))
+
+	copy(newList, list)
+
+	newList[newPos] = list[oldPos]
+
+	if newPos < oldPos {
+		for i := newPos; i <= oldPos; i++ {
+			if i != oldPos {
+				newList[i+1] = list[i]
+			}
+		}
+
+		return newList
+	}
+
+	for i := oldPos; i <= newPos; i++ {
+		if i != oldPos {
+			newList[i-1] = list[i]
+		}
+	}
+
+	return newList
+}

experiments/go/shuffle-elements/shuffle_test.go

@@ -1,57 +1,66 @@
 package main
 
 import (
-	"fmt"
 	"reflect"
 	"testing"
 )
 
-func TestShuffle(t *testing.T) {
+type Cases struct {
-	cases := []struct {
+	list        []any
-		list        []any
+	oldPosition int
-		oldPosition int
+	newPosition int
-		newPosition int
+	want        []any
-		want        []any
-	}{
-		{
-			list:        []any{1, 2, 3, 4, 5, 6, 7, 8},
-			oldPosition: 5,
-			newPosition: 2,
-			want:        []any{1, 2, 6, 3, 4, 5, 7, 8},
-		},
-		{
-			list:        []any{1, 2, 3, 4, 5, 6, 7, 8},
-			oldPosition: 7,
-			newPosition: 0,
-			want:        []any{8, 1, 2, 3, 4, 5, 6, 7},
-		},
-		{
-			list:        []any{"zero", "one", "two", "three", "four", "five"},
-			oldPosition: 0,
-			newPosition: 5,
-			want:        []any{"one", "two", "three", "four", "five", "zero"},
-		},
-		{
-			list:        []any{"zero", "one", "two", "three", "four", "five"},
-			oldPosition: 2,
-			newPosition: 3,
-			want:        []any{"zero", "one", "three", "two", "four", "five"},
-		},
-	}
-
-	for i := range cases {
-		t.Run(fmt.Sprintf("Test Case %d", i), testFunc(cases[i].list, cases[i].oldPosition, cases[i].newPosition, cases[i].want))
-	}
 }
 
-func testFunc(list []any, oldPosition, newPosition int, want []any) func(t *testing.T) {
+var cases = []Cases{
-	return func(t *testing.T) {
+	{
-		t.Logf("Input list: %v", list)
+		list:        []any{1, 2, 3, 4, 5, 6, 7, 8},
-		t.Logf("We want '%v' to move to position %d", list[oldPosition], newPosition)
+		oldPosition: 5,
+		newPosition: 2,
+		want:        []any{1, 2, 6, 3, 4, 5, 7, 8},
+	},
+	{
+		list:        []any{1, 2, 3, 4, 5, 6, 7, 8},
+		oldPosition: 7,
+		newPosition: 0,
+		want:        []any{8, 1, 2, 3, 4, 5, 6, 7},
+	},
+	{
+		list:        []any{"zero", "one", "two", "three", "four", "five"},
+		oldPosition: 0,
+		newPosition: 5,
+		want:        []any{"one", "two", "three", "four", "five", "zero"},
+	},
+	{
+		list:        []any{"zero", "one", "two", "three", "four", "five"},
+		oldPosition: 2,
+		newPosition: 3,
+		want:        []any{"zero", "one", "three", "two", "four", "five"},
+	},
+}
 
-		got := shuffle(list, oldPosition, newPosition)
+func TestShuffleFuncOne(t *testing.T) {
-		if !reflect.DeepEqual(want, got) {
+	for i := range cases {
-			t.Errorf("TEST FAILED: want: %v, got %v", want, got)
+		t.Logf("Input list: %v", cases[i].list)
+		t.Logf("We want '%v' to move to position %d", cases[i].list[cases[i].oldPosition], cases[i].newPosition)
+
+		got := shuffleFuncOne(cases[i].list, cases[i].oldPosition, cases[i].newPosition)
+		if !reflect.DeepEqual(cases[i].want, got) {
+			t.Errorf("TEST FAILED: want: %v, got %v", cases[i].want, got)
+		} else {
+			t.Logf("TEST PASSED: got %v", got)
+		}
+	}
+}
+
+func TestShuffleFuncTwo(t *testing.T) {
+	for i := range cases {
+		t.Logf("Input list: %v", cases[i].list)
+		t.Logf("We want '%v' to move to position %d", cases[i].list[cases[i].oldPosition], cases[i].newPosition)
+
+		got := shuffleFuncTwo(cases[i].list, cases[i].oldPosition, cases[i].newPosition)
+		if !reflect.DeepEqual(cases[i].want, got) {
+			t.Errorf("TEST FAILED: want: %v, got %v", cases[i].want, got)
 		} else {
 			t.Logf("TEST PASSED: got %v", got)
 		}