Add 'allergies' exercise

config.json

@@ -5,6 +5,7 @@
   "checklist_issue": 8,
   "active": false,
   "problems": [
+    "allergies",
     "hello-world",
     "anagram",
     "leap",
@@ -23,6 +24,15 @@
     "binary-search"
   ],
   "exercises": [{
+    "slug": "allergies",
+    "difficulty": 4,
+    "topics": [
+      "control-flow (if-statements)",
+      "control-flow (loops)",
+      "structs",
+      "memory management"
+    ]
+  }, {
     "slug": "hello-world",
     "difficulty": 1,
     "topics": [

exercises/allergies/makefile

@@ -0,0 +1,15 @@
+CFLAGS  = -std=c99
+CFLAGS += -Wall
+CFLAGS += -Wextra
+CFLAGS += -pedantic
+CFLAGS += -Werror
+
+test: tests.out
+	@./tests.out
+
+clean:
+	rm -f *.o *.out
+
+tests.out: test/test_allergies.c src/allergies.c src/allergies.h
+	@echo Compiling $@
+	@cc $(CFLAGS) src/allergies.c test/vendor/unity.c test/test_allergies.c -o tests.out

exercises/allergies/src/allergies.h

@@ -0,0 +1,21 @@
+#ifndef _ALLERGIES_H
+#define _ALLERGIES_H
+
+typedef enum {
+   Allergen_Eggs = 0,
+   Allergen_Peanuts,
+   Allergen_Shellfish,
+   Allergen_Strawberries,
+   Allergen_Tomatoes,
+   Allergen_Chocolate,
+   Allergen_Pollen,
+   Allergen_Cats,
+   Allergen_Count
+} Allergen_t;
+
+typedef struct {
+   int count;
+   Allergen_t *allergens;
+} Allergen_List_t;
+
+#endif

exercises/allergies/src/example.c

@@ -0,0 +1,32 @@
+#include "allergies.h"
+#include <stdlib.h>
+
+static const unsigned int scores[] = {
+   1,
+   2,
+   4,
+   8,
+   16,
+   32,
+   64,
+   128
+};
+
+bool is_allergic_to(Allergen_t allergen, unsigned int score)
+{
+   return ((score & scores[allergen]) == scores[allergen]);
+}
+
+void get_allergens(int score, Allergen_List_t * list)
+{
+   list->allergens = calloc(Allergen_Count, sizeof(Allergen_t));
+   list->count = 0;
+
+   for (Allergen_t allergen = 0; allergen < Allergen_Count; allergen++) {
+      if (is_allergic_to(allergen, score)) {
+         score -= scores[allergen];
+         list->allergens[list->count] = allergen;
+         list->count++;
+      }
+   }
+}

exercises/allergies/src/example.h

@@ -0,0 +1,26 @@
+#ifndef _ALLERGIES_H
+#define _ALLERGIES_H
+
+#include <stdbool.h>
+
+typedef enum {
+   Allergen_Eggs = 0,
+   Allergen_Peanuts,
+   Allergen_Shellfish,
+   Allergen_Strawberries,
+   Allergen_Tomatoes,
+   Allergen_Chocolate,
+   Allergen_Pollen,
+   Allergen_Cats,
+   Allergen_Count
+} Allergen_t;
+
+typedef struct {
+   int count;
+   Allergen_t *allergens;
+} Allergen_List_t;
+
+bool is_allergic_to(Allergen_t allergen, unsigned int score);
+void get_allergens(int score, Allergen_List_t * list);
+
+#endif

exercises/allergies/test/test_allergies.c

@@ -0,0 +1,203 @@
+#include "vendor/unity.h"
+#include "../src/allergies.h"
+#include <stdlib.h>
+
+void test_list_count_is(int count, Allergen_List_t * list)
+{
+   TEST_ASSERT_EQUAL(count, list->count);
+}
+
+void test_list_contains(Allergen_t allergen, Allergen_List_t * list)
+{
+   bool allergen_found = false;
+
+   for (int i = 0; i < list->count; i++) {
+      if (list->allergens[i] == allergen) {
+         allergen_found = true;
+         break;
+      }
+   }
+
+   TEST_ASSERT_TRUE(allergen_found);
+}
+
+void test_no_allergies_means_not_allergic(void)
+{
+   int score = 0;
+
+   TEST_ASSERT_FALSE(is_allergic_to(Allergen_Peanuts, score));
+   TEST_ASSERT_FALSE(is_allergic_to(Allergen_Cats, score));
+   TEST_ASSERT_FALSE(is_allergic_to(Allergen_Strawberries, score));
+}
+
+void test_is_allergic_to_eggs(void)
+{
+   int score = 1;
+
+   TEST_ASSERT_TRUE(is_allergic_to(Allergen_Eggs, score));
+}
+
+void test_is_allergic_to_eggs_in_addition_to_other_stuff(void)
+{
+   int score = 5;
+
+   TEST_ASSERT_TRUE(is_allergic_to(Allergen_Eggs, score));
+   TEST_ASSERT_TRUE(is_allergic_to(Allergen_Shellfish, score));
+   TEST_ASSERT_FALSE(is_allergic_to(Allergen_Strawberries, score));
+}
+
+void test_no_allergies_at_all(void)
+{
+   int score = 0;
+   Allergen_List_t list;
+
+   get_allergens(score, &list);
+
+   test_list_count_is(0, &list);
+
+   free(list.allergens);
+}
+
+void test_allergic_to_just_eggs(void)
+{
+   int score = 1;
+   Allergen_List_t list;
+
+   get_allergens(score, &list);
+
+   test_list_count_is(1, &list);
+   test_list_contains(Allergen_Eggs, &list);
+
+   free(list.allergens);
+}
+
+void test_allergic_to_just_peanuts(void)
+{
+   int score = 2;
+   Allergen_List_t list;
+
+   get_allergens(score, &list);
+
+   test_list_count_is(1, &list);
+   test_list_contains(Allergen_Peanuts, &list);
+
+   free(list.allergens);
+}
+
+void test_allergic_to_just_strawberries(void)
+{
+   int score = 8;
+   Allergen_List_t list;
+
+   get_allergens(score, &list);
+
+   test_list_count_is(1, &list);
+   test_list_contains(Allergen_Strawberries, &list);
+
+   free(list.allergens);
+}
+
+void test_allergic_to_eggs_and_peanuts(void)
+{
+   int score = 3;
+   Allergen_List_t list;
+
+   get_allergens(score, &list);
+
+   test_list_count_is(2, &list);
+   test_list_contains(Allergen_Eggs, &list);
+   test_list_contains(Allergen_Peanuts, &list);
+
+   free(list.allergens);
+}
+
+void test_allergic_to_more_than_eggs_but_not_peanuts(void)
+{
+   int score = 5;
+   Allergen_List_t list;
+
+   get_allergens(score, &list);
+
+   test_list_count_is(2, &list);
+   test_list_contains(Allergen_Eggs, &list);
+   test_list_contains(Allergen_Shellfish, &list);
+
+   free(list.allergens);
+}
+
+void test_allergic_to_lots_of_stuff(void)
+{
+   int score = 248;
+   Allergen_List_t list;
+
+   get_allergens(score, &list);
+
+   test_list_count_is(5, &list);
+   test_list_contains(Allergen_Strawberries, &list);
+   test_list_contains(Allergen_Tomatoes, &list);
+   test_list_contains(Allergen_Chocolate, &list);
+   test_list_contains(Allergen_Pollen, &list);
+   test_list_contains(Allergen_Cats, &list);
+
+   free(list.allergens);
+}
+
+void test_allergic_to_everything(void)
+{
+   int score = 255;
+   Allergen_List_t list;
+
+   get_allergens(score, &list);
+
+   test_list_count_is(8, &list);
+   test_list_contains(Allergen_Eggs, &list);
+   test_list_contains(Allergen_Peanuts, &list);
+   test_list_contains(Allergen_Shellfish, &list);
+   test_list_contains(Allergen_Strawberries, &list);
+   test_list_contains(Allergen_Tomatoes, &list);
+   test_list_contains(Allergen_Chocolate, &list);
+   test_list_contains(Allergen_Pollen, &list);
+   test_list_contains(Allergen_Cats, &list);
+
+   free(list.allergens);
+}
+
+void test_ignore_non_allergen_score_parts(void)
+{
+   int score = 509;
+   Allergen_List_t list;
+
+   get_allergens(score, &list);
+
+   test_list_count_is(7, &list);
+   test_list_contains(Allergen_Eggs, &list);
+   test_list_contains(Allergen_Shellfish, &list);
+   test_list_contains(Allergen_Strawberries, &list);
+   test_list_contains(Allergen_Tomatoes, &list);
+   test_list_contains(Allergen_Chocolate, &list);
+   test_list_contains(Allergen_Pollen, &list);
+   test_list_contains(Allergen_Cats, &list);
+
+   free(list.allergens);
+}
+
+int main(void)
+{
+   UnityBegin("test/test_allergies.c");
+
+   RUN_TEST(test_no_allergies_means_not_allergic);
+   RUN_TEST(test_is_allergic_to_eggs);
+   RUN_TEST(test_is_allergic_to_eggs_in_addition_to_other_stuff);
+   RUN_TEST(test_no_allergies_at_all);
+   RUN_TEST(test_allergic_to_just_eggs);
+   RUN_TEST(test_allergic_to_just_peanuts);
+   RUN_TEST(test_allergic_to_just_strawberries);
+   RUN_TEST(test_allergic_to_eggs_and_peanuts);
+   RUN_TEST(test_allergic_to_more_than_eggs_but_not_peanuts);
+   RUN_TEST(test_allergic_to_lots_of_stuff);
+   RUN_TEST(test_allergic_to_everything);
+   RUN_TEST(test_ignore_non_allergen_score_parts);
+
+   UnityEnd();
+   return 0;
+}