update: slice exercises 21, 23, 24, 25, 26

16-slices/exercises/21-correct-the-lyric/hints.md

@@ -0,0 +1,17 @@
+# Hints
+
+You can use the following slice operations to solve the exercise:
+
++ Prepends "value" to the slice:
+  ```go
+  slice = append([]string{"value"}, slice...)
+  ```
+
++ Appends some part (N to M) of the same slice to itself:
+  ```go
+  slice = append(slice, slice[N:M]...)
+  ```
++ Copies the last part of the slice starting from M to the first part of the slice until N:
+  ```go
+  slice = append(slice[:N], slice[M:]...)
+  ```

16-slices/exercises/21-correct-the-lyric/main.go

@@ -51,18 +51,7 @@ import (
 //
 // HINTS
 //
-//   Only look at this if you get stuck.
-//
-//   You can use the following slice operations to solve the exercise.
-//
-//   + Prepends "value" to the slice:
-//     slice = append([]string{"value"}, slice...)
-//
-//   + Appends some part (N to M) of the same slice to itself:
-//     slice = append(slice, slice[N:M]...)
-//
-//   + Copies the last part of the slice starting from M to the first part of the slice until N:
-//     slice = append(slice[:N], slice[M:]...)
+//   If you get stuck, check out the hints.md file.
 //
 // ---------------------------------------------------------