Add scrabble-score exercise (#94)

config.json

@@ -154,6 +154,14 @@
         "prerequisites": [],
         "difficulty": 3
       },
+      {
+        "slug": "scrabble-score",
+        "name": "Scrabble Score",
+        "uuid": "4c543626-0230-408a-8da4-ee0cd98ce7c0",
+        "practices": [],
+        "prerequisites": [],
+        "difficulty": 3
+      },
       {
         "slug": "square-root",
         "name": "Square Root",

exercises/practice/scrabble-score/.docs/instructions.md

@@ -0,0 +1,25 @@
+# Instructions
+
+Your task is to compute a word's Scrabble score by summing the values of its letters.
+
+The letters are valued as follows:
+
+| Letter                       | Value |
+| ---------------------------- | ----- |
+| A, E, I, O, U, L, N, R, S, T | 1     |
+| D, G                         | 2     |
+| B, C, M, P                   | 3     |
+| F, H, V, W, Y                | 4     |
+| K                            | 5     |
+| J, X                         | 8     |
+| Q, Z                         | 10    |
+
+For example, the word "cabbage" is worth 14 points:
+
+- 3 points for C
+- 1 point for A
+- 3 points for B
+- 3 points for B
+- 1 point for A
+- 2 points for G
+- 1 point for E

exercises/practice/scrabble-score/.docs/introduction.md

@@ -0,0 +1,7 @@
+# Introduction
+
+[Scrabble][wikipedia] is a word game where players place letter tiles on a board to form words.
+Each letter has a value.
+A word's score is the sum of its letters' values.
+
+[wikipedia]: https://en.wikipedia.org/wiki/Scrabble

exercises/practice/scrabble-score/.meta/config.json

@@ -0,0 +1,19 @@
+{
+  "authors": [
+    "keiravillekode"
+  ],
+  "files": {
+    "solution": [
+      "scrabble_score.s"
+    ],
+    "test": [
+      "scrabble_score_test.c"
+    ],
+    "example": [
+      ".meta/example.s"
+    ]
+  },
+  "blurb": "Given a word, compute the Scrabble score for that word.",
+  "source": "Inspired by the Extreme Startup game",
+  "source_url": "https://github.com/rchatley/extreme_startup"
+}

exercises/practice/scrabble-score/.meta/example.s

@@ -0,0 +1,27 @@
+.data
+table: .byte 1, 3, 3, 2, 1, 4, 2, 4, 1, 8, 5, 1, 3, 1, 1, 3, 10, 1, 1, 1, 1, 4, 4, 8, 4, 10
+
+.text
+.globl score
+
+/* extern int score(const char *word); */
+score:
+        adr     x1, table
+        mov     x2, x0                  /* pointer into word */
+        mov     w0, #0                  /* result */
+
+.read:
+        ldrb    w3, [x2], #1            /* load byte, with post-increment */
+        cbz     w3, .return
+
+        orr     w3, w3, #32             /* force lower case */
+        sub     w3, w3, #'a'
+        cmp     w3, #26
+        bhs     .read                   /* unsigned >= */
+
+        ldrb    w4, [x1, x3]            /* load byte from table */
+        add     w0, w0, w4              /* accumulate result */
+        b       .read
+
+.return:
+        ret

exercises/practice/scrabble-score/.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.
+
+[f46cda29-1ca5-4ef2-bd45-388a767e3db2]
+description = "lowercase letter"
+
+[f7794b49-f13e-45d1-a933-4e48459b2201]
+description = "uppercase letter"
+
+[eaba9c76-f9fa-49c9-a1b0-d1ba3a5b31fa]
+description = "valuable letter"
+
+[f3c8c94e-bb48-4da2-b09f-e832e103151e]
+description = "short word"
+
+[71e3d8fa-900d-4548-930e-68e7067c4615]
+description = "short, valuable word"
+
+[d3088ad9-570c-4b51-8764-c75d5a430e99]
+description = "medium word"
+
+[fa20c572-ad86-400a-8511-64512daac352]
+description = "medium, valuable word"
+
+[9336f0ba-9c2b-4fa0-bd1c-2e2d328cf967]
+description = "long, mixed-case word"
+
+[1e34e2c3-e444-4ea7-b598-3c2b46fd2c10]
+description = "english-like word"
+
+[4efe3169-b3b6-4334-8bae-ff4ef24a7e4f]
+description = "empty input"
+
+[3b305c1c-f260-4e15-a5b5-cb7d3ea7c3d7]
+description = "entire alphabet available"

exercises/practice/scrabble-score/Makefile

@@ -0,0 +1,36 @@
+AS = aarch64-linux-gnu-as
+CC = aarch64-linux-gnu-gcc
+
+CFLAGS = -g -Wall -Wextra -pedantic -Werror
+LDFLAGS =
+
+ALL_LDFLAGS = -pie -Wl,--fatal-warnings
+
+ALL_CFLAGS = -std=c99 -fPIE $(CFLAGS)
+ALL_LDFLAGS += $(LDFLAGS)
+
+C_OBJS = $(patsubst %.c,%.o,$(wildcard *.c))
+AS_OBJS = $(patsubst %.s,%.o,$(wildcard *.s))
+ALL_OBJS = $(filter-out example.o,$(C_OBJS) $(AS_OBJS) vendor/unity.o)
+
+CC_CMD = $(CC) $(ALL_CFLAGS) -c -o $@ $<
+
+all: tests
+	qemu-aarch64 -L /usr/aarch64-linux-gnu ./$<
+
+tests: $(ALL_OBJS)
+	@$(CC) $(ALL_CFLAGS) $(ALL_LDFLAGS) -o $@ $(ALL_OBJS)
+
+%.o: %.s
+	@$(AS) -o $@ $<
+
+%.o: %.c
+	@$(CC_CMD)
+
+vendor/unity.o: vendor/unity.c vendor/unity.h vendor/unity_internals.h
+	@$(CC_CMD)
+
+clean:
+	@rm -f *.o vendor/*.o tests
+
+.PHONY: all clean

exercises/practice/scrabble-score/scrabble_score.s

@@ -0,0 +1,5 @@
+.text
+.globl score
+
+score:
+    ret

exercises/practice/scrabble-score/scrabble_score_test.c

@@ -0,0 +1,79 @@
+#include "vendor/unity.h"
+
+extern int score(const char *word);
+
+void setUp(void) {
+}
+
+void tearDown(void) {
+}
+
+void test_lowercase_letter(void) {
+    TEST_ASSERT_EQUAL_INT(1, score("a"));
+}
+
+void test_uppercase_letter(void) {
+    TEST_IGNORE();
+    TEST_ASSERT_EQUAL_INT(1, score("A"));
+}
+
+void test_valuable_letter(void) {
+    TEST_IGNORE();
+    TEST_ASSERT_EQUAL_INT(4, score("f"));
+}
+
+void test_short_word(void) {
+    TEST_IGNORE();
+    TEST_ASSERT_EQUAL_INT(2, score("at"));
+}
+
+void test_short_valuable_word(void) {
+    TEST_IGNORE();
+    TEST_ASSERT_EQUAL_INT(12, score("zoo"));
+}
+
+void test_medium_word(void) {
+    TEST_IGNORE();
+    TEST_ASSERT_EQUAL_INT(6, score("street"));
+}
+
+void test_medium_valuable_word(void) {
+    TEST_IGNORE();
+    TEST_ASSERT_EQUAL_INT(22, score("quirky"));
+}
+
+void test_long_mixedcase_word(void) {
+    TEST_IGNORE();
+    TEST_ASSERT_EQUAL_INT(41, score("OxyphenButazone"));
+}
+
+void test_englishlike_word(void) {
+    TEST_IGNORE();
+    TEST_ASSERT_EQUAL_INT(8, score("pinata"));
+}
+
+void test_empty_input(void) {
+    TEST_IGNORE();
+    TEST_ASSERT_EQUAL_INT(0, score(""));
+}
+
+void test_entire_alphabet_available(void) {
+    TEST_IGNORE();
+    TEST_ASSERT_EQUAL_INT(87, score("abcdefghijklmnopqrstuvwxyz"));
+}
+
+int main(void) {
+    UNITY_BEGIN();
+    RUN_TEST(test_lowercase_letter);
+    RUN_TEST(test_uppercase_letter);
+    RUN_TEST(test_valuable_letter);
+    RUN_TEST(test_short_word);
+    RUN_TEST(test_short_valuable_word);
+    RUN_TEST(test_medium_word);
+    RUN_TEST(test_medium_valuable_word);
+    RUN_TEST(test_long_mixedcase_word);
+    RUN_TEST(test_englishlike_word);
+    RUN_TEST(test_empty_input);
+    RUN_TEST(test_entire_alphabet_available);
+    return UNITY_END();
+}