Solved Beautiful Permutations exercise

introductory.go

@@ -78,3 +78,29 @@ func IncreasingArray(size int, arr []int) int {
 
 	return moves
 }
+
+func BeautifulPermutations(n int) string {
+	result := []int{}
+
+	if n <= 3 {
+		return "NO SOLUTION"
+	}
+
+	if n == 4 {
+		result = []int{3, 1, 4, 2}
+	} else {
+		curr := n
+		switched := false
+		for i := 1; i <= n; i++ {
+			result = append(result, curr)
+			if curr < 3 && !switched {
+				curr = n - 1
+				switched = true
+			} else {
+				curr = curr - 2
+			}
+		}
+	}
+
+	return fmt.Sprint(result)
+}

introductory_test.go

@@ -26,3 +26,15 @@ func TestIncreasingArray(t *testing.T) {
 	assert.Equal(t, 0, IncreasingArray(5, []int{3}))
 	assert.Equal(t, 5, IncreasingArray(5, []int{3, 2, 5, 1, 7}))
 }
+
+func TestBeautifulPermutations(t *testing.T) {
+	assert.Equal(t, "NO SOLUTION", BeautifulPermutations(2))
+	assert.Equal(t, "NO SOLUTION", BeautifulPermutations(3))
+	assert.Equal(t, "[3 1 4 2]", BeautifulPermutations(4))
+	assert.Equal(t, "[5 3 1 4 2]", BeautifulPermutations(5))
+	assert.Equal(t, "[6 4 2 5 3 1]", BeautifulPermutations(6))
+	assert.Equal(t, "[7 5 3 1 6 4 2]", BeautifulPermutations(7))
+	assert.Equal(t, "[8 6 4 2 7 5 3 1]", BeautifulPermutations(8))
+	assert.Equal(t, "[9 7 5 3 1 8 6 4 2]", BeautifulPermutations(9))
+	assert.Equal(t, 48895, len(BeautifulPermutations(10000)))
+}