diff --git a/config.json b/config.json index 36a93ae6..e5c26429 100644 --- a/config.json +++ b/config.json @@ -512,6 +512,14 @@ "strings" ] }, + { + "slug": "secret-handshake", + "name": "Secret Handshake", + "uuid": "e55f5562-9126-4cc7-9f9e-a3cbdfd292b4", + "practices": [], + "prerequisites": [], + "difficulty": 3 + }, { "slug": "series", "name": "Series", diff --git a/exercises/practice/secret-handshake/.docs/instructions.md b/exercises/practice/secret-handshake/.docs/instructions.md new file mode 100644 index 00000000..d2120b9b --- /dev/null +++ b/exercises/practice/secret-handshake/.docs/instructions.md @@ -0,0 +1,48 @@ +# Instructions + +Your task is to convert a number between 1 and 31 to a sequence of actions in the secret handshake. + +The sequence of actions is chosen by looking at the rightmost five digits of the number once it's been converted to binary. +Start at the right-most digit and move left. + +The actions for each number place are: + +```plaintext +00001 = wink +00010 = double blink +00100 = close your eyes +01000 = jump +10000 = Reverse the order of the operations in the secret handshake. +``` + +Let's use the number `9` as an example: + +- 9 in binary is `1001`. +- The digit that is farthest to the right is 1, so the first action is `wink`. +- Going left, the next digit is 0, so there is no double-blink. +- Going left again, the next digit is 0, so you leave your eyes open. +- Going left again, the next digit is 1, so you jump. + +That was the last digit, so the final code is: + +```plaintext +wink, jump +``` + +Given the number 26, which is `11010` in binary, we get the following actions: + +- double blink +- jump +- reverse actions + +The secret handshake for 26 is therefore: + +```plaintext +jump, double blink +``` + +~~~~exercism/note +If you aren't sure what binary is or how it works, check out [this binary tutorial][intro-to-binary]. + +[intro-to-binary]: https://medium.com/basecs/bits-bytes-building-with-binary-13cb4289aafa +~~~~ diff --git a/exercises/practice/secret-handshake/.docs/introduction.md b/exercises/practice/secret-handshake/.docs/introduction.md new file mode 100644 index 00000000..176b92e8 --- /dev/null +++ b/exercises/practice/secret-handshake/.docs/introduction.md @@ -0,0 +1,7 @@ +# Introduction + +You are starting a secret coding club with some friends and friends-of-friends. +Not everyone knows each other, so you and your friends have decided to create a secret handshake that you can use to recognize that someone is a member. +You don't want anyone who isn't in the know to be able to crack the code. + +You've designed the code so that one person says a number between 1 and 31, and the other person turns it into a series of actions. diff --git a/exercises/practice/secret-handshake/.meta/config.json b/exercises/practice/secret-handshake/.meta/config.json new file mode 100644 index 00000000..ec07121c --- /dev/null +++ b/exercises/practice/secret-handshake/.meta/config.json @@ -0,0 +1,19 @@ +{ + "authors": [ + "keiravillekode" + ], + "files": { + "solution": [ + "secret-handshake.el" + ], + "test": [ + "secret-handshake-test.el" + ], + "example": [ + ".meta/example.el" + ] + }, + "blurb": "Given a decimal number, convert it to the appropriate sequence of events for a secret handshake.", + "source": "Bert, in Mary Poppins", + "source_url": "https://www.imdb.com/title/tt0058331/quotes/?item=qt0437047" +} diff --git a/exercises/practice/secret-handshake/.meta/example.el b/exercises/practice/secret-handshake/.meta/example.el new file mode 100644 index 00000000..8271b79f --- /dev/null +++ b/exercises/practice/secret-handshake/.meta/example.el @@ -0,0 +1,26 @@ +;;; secret-handshake.el --- Secret Handshake (exercism) -*- lexical-binding: t; -*- + +;;; Commentary: + +;;; Code: + +(require 'cl-lib) + +(defun commands (number) + (let ((all-commands '("wink" "double blink" "close your eyes" "jump")) + (result nil)) + (cl-labels + ((extract (action shift pending) + (cl-loop until (null pending) + if (/= (logand number action) 0) + do (setq result (cons (car pending) result)) + do (setq pending (cdr pending)) + do (setq action (lsh action shift)) + finally return result))) + (if (= (logand number 16) 0) + (funcall #'extract 8 -1 (reverse all-commands)) + (funcall #'extract 1 1 all-commands))))) + +(provide 'secret-handshake) +;;; secret-handshake.el ends here + diff --git a/exercises/practice/secret-handshake/.meta/tests.toml b/exercises/practice/secret-handshake/.meta/tests.toml new file mode 100644 index 00000000..f318e528 --- /dev/null +++ b/exercises/practice/secret-handshake/.meta/tests.toml @@ -0,0 +1,43 @@ +# This is an auto-generated file. +# +# Regenerating this file via `configlet sync` will: +# - Recreate every `description` key/value pair +# - Recreate every `reimplements` key/value pair, where they exist in problem-specifications +# - Remove any `include = true` key/value pair (an omitted `include` key implies inclusion) +# - Preserve any other key/value pair +# +# As user-added comments (using the # character) will be removed when this file +# is regenerated, comments can be added via a `comment` key. + +[b8496fbd-6778-468c-8054-648d03c4bb23] +description = "wink for 1" + +[83ec6c58-81a9-4fd1-bfaf-0160514fc0e3] +description = "double blink for 10" + +[0e20e466-3519-4134-8082-5639d85fef71] +description = "close your eyes for 100" + +[b339ddbb-88b7-4b7d-9b19-4134030d9ac0] +description = "jump for 1000" + +[40499fb4-e60c-43d7-8b98-0de3ca44e0eb] +description = "combine two actions" + +[9730cdd5-ef27-494b-afd3-5c91ad6c3d9d] +description = "reverse two actions" + +[0b828205-51ca-45cd-90d5-f2506013f25f] +description = "reversing one action gives the same action" + +[9949e2ac-6c9c-4330-b685-2089ab28b05f] +description = "reversing no actions still gives no actions" + +[23fdca98-676b-4848-970d-cfed7be39f81] +description = "all possible actions" + +[ae8fe006-d910-4d6f-be00-54b7c3799e79] +description = "reverse all possible actions" + +[3d36da37-b31f-4cdb-a396-d93a2ee1c4a5] +description = "do nothing for zero" diff --git a/exercises/practice/secret-handshake/secret-handshake-test.el b/exercises/practice/secret-handshake/secret-handshake-test.el new file mode 100644 index 00000000..9ef4e020 --- /dev/null +++ b/exercises/practice/secret-handshake/secret-handshake-test.el @@ -0,0 +1,57 @@ +;;; secret-handshake-test.el --- Tests for Secret Handshake (exercism) -*- lexical-binding: t; -*- + +;;; Commentary: + +;;; Code: + + +(load-file "secret-handshake.el") +(declare-function commands "secret-handshake.el" (number)) + + +(ert-deftest wink-for-1 () + (should (equal '("wink") (commands 1)))) + + +(ert-deftest double-blink-for-10 () + (should (equal '("double blink") (commands 2)))) + + +(ert-deftest close-your-eyes-for-100 () + (should (equal '("close your eyes") (commands 4)))) + + +(ert-deftest jump-for-1000 () + (should (equal '("jump") (commands 8)))) + + +(ert-deftest combine-two-actions () + (should (equal '("wink" "double blink") (commands 3)))) + + +(ert-deftest reverse-two-actions () + (should (equal '("double blink" "wink") (commands 19)))) + + +(ert-deftest reversing-one-action-gives-the-same-action () + (should (equal '("jump") (commands 24)))) + + +(ert-deftest reversing-no-actions-still-gives-no-actions () + (should (equal '() (commands 16)))) + + +(ert-deftest all-possible-actions () + (should (equal '("wink" "double blink" "close your eyes" "jump") (commands 15)))) + + +(ert-deftest reverse-all-possible-actions () + (should (equal '("jump" "close your eyes" "double blink" "wink") (commands 31)))) + + +(ert-deftest do-nothing-for-zero () + (should (equal '() (commands 0)))) + + +(provide 'secret-handshake-test) +;;; secret-handshake-test.el ends here diff --git a/exercises/practice/secret-handshake/secret-handshake.el b/exercises/practice/secret-handshake/secret-handshake.el new file mode 100644 index 00000000..d6dbf7ea --- /dev/null +++ b/exercises/practice/secret-handshake/secret-handshake.el @@ -0,0 +1,14 @@ +;;; secret-handshake.el --- Secret Handshake (exercism) -*- lexical-binding: t; -*- + +;;; Commentary: + +;;; Code: + + +(defun commands (number) + (error "Delete this S-Expression and write your own implementation")) + + +(provide 'secret-handshake) +;;; secret-handshake.el ends here +