Add resistor-color-duo exercise (#187)

config.json

@@ -107,6 +107,17 @@
           "arrays"
         ]
       },
+      {
+        "slug": "resistor-color-duo",
+        "name": "Resistor Color Duo",
+        "uuid": "d2a983d7-3e9a-43fd-a916-23d51401c68e",
+        "practices": [],
+        "prerequisites": [],
+        "difficulty": 3,
+        "topics": [
+          "arrays"
+        ]
+      },
       {
         "slug": "space-age",
         "name": "Space Age",

exercises/practice/resistor-color-duo/.docs/instructions.md

@@ -0,0 +1,33 @@
+# Instructions
+
+If you want to build something using a Raspberry Pi, you'll probably use _resistors_.
+For this exercise, you need to know two things about them:
+
+- Each resistor has a resistance value.
+- Resistors are small - so small in fact that if you printed the resistance value on them, it would be hard to read.
+
+To get around this problem, manufacturers print color-coded bands onto the resistors to denote their resistance values.
+Each band has a position and a numeric value.
+
+The first 2 bands of a resistor have a simple encoding scheme: each color maps to a single number.
+For example, if they printed a brown band (value 1) followed by a green band (value 5), it would translate to the number 15.
+
+In this exercise you are going to create a helpful program so that you don't have to remember the values of the bands.
+The program will take color names as input and output a two digit number, even if the input is more than two colors!
+
+The band colors are encoded as follows:
+
+- Black: 0
+- Brown: 1
+- Red: 2
+- Orange: 3
+- Yellow: 4
+- Green: 5
+- Blue: 6
+- Violet: 7
+- Grey: 8
+- White: 9
+
+From the example above:
+brown-green should return 15
+brown-green-violet should return 15 too, ignoring the third color.

exercises/practice/resistor-color-duo/.gitignore

@@ -0,0 +1,2 @@
+*.o
+tests

exercises/practice/resistor-color-duo/.meta/config.json

@@ -0,0 +1,19 @@
+{
+  "authors": [
+    "keiravillekode"
+  ],
+  "files": {
+    "solution": [
+      "resistor_color_duo.asm"
+    ],
+    "test": [
+      "resistor_color_duo_test.c"
+    ],
+    "example": [
+      ".meta/example.asm"
+    ]
+  },
+  "blurb": "Convert color codes, as used on resistors, to a numeric value.",
+  "source": "Maud de Vries, Erik Schierboom",
+  "source_url": "https://github.com/exercism/problem-specifications/issues/1464"
+}

exercises/practice/resistor-color-duo/.meta/example.asm

@@ -0,0 +1,108 @@
+default rel
+
+; From the resistor-color exercise
+section .rodata
+black: db "black", 0
+brown: db "brown", 0
+red: db "red", 0
+orange: db "orange", 0
+yellow: db "yellow", 0
+green: db "green", 0
+blue: db "blue", 0
+violet: db "violet", 0
+grey: db "grey", 0
+white: db "white", 0
+
+; From the resistor-color exercise
+section .data
+color_array:
+dq black
+dq brown
+dq red
+dq orange
+dq yellow
+dq green
+dq blue
+dq violet
+dq grey
+dq white
+dq 0  ; Sentinel value to indicate end of array
+
+section .text
+global value
+value:
+;
+; Convert from resistor band colors to the numeric representation.
+;
+; Parameters:
+;   rdi - address of first input string
+;   rsi - address of second input string
+;   rdx - address of third input string, or 0 (NULL)
+; Returns:
+;   rax - numeric value of resistor's first two color codes
+;
+    mov r9, rsi
+    call color_code
+    mov rdx, 10
+    mul rdx
+    mov r10, rax
+    mov rdi, r9
+    call color_code
+    add rax, r10
+    ret
+
+; From the resistor-color exercise
+
+;
+; Convert a resistor band's color to its numeric representation.
+;
+; Parameters:
+;   rdi - color
+; Returns:
+;   rax - the resistor band's numeric representation or -1 if not found
+;
+color_code:
+    xor eax, eax              ; Initialize array index
+    lea rcx, [color_array]    ; Load color array
+    mov rdx, [rcx + rax * 8]  ; Read color from array
+.arr_loop_start:
+    mov rsi, rdi              ; Save input color
+
+    mov r8b, byte [rdx]       ; Read char from color
+    cmp r8b, byte [rsi]       ; Compare with char from input color
+    jne .str_loop_end         ; If not equal, skip loop
+.str_loop_start:
+    inc rdx                   ; Advance color to next char
+    inc rsi                   ; Advance input color to next char
+    mov r8b, byte [rdx]       ; Read char from color
+    cmp r8b, byte [rsi]       ; Compare with char from input color
+    jne .str_loop_end         ; If not equal, exit loop
+    test r8b, r8b             ; See if we reached end of color
+    jne .str_loop_start       ; If chars remain, loop back
+
+.str_loop_end:
+    cmp r8b, byte [rsi]       ; Check if we found a match
+    je .return                ; If we found a match, return the array index
+    inc eax                   ; Increment array index
+    mov rdx, [rcx + rax * 8]  ; Read color from array
+    test rdx, rdx             ; See if we reached end of array
+    jne .arr_loop_start       ; If colors remain, loop back
+
+    mov eax, -1               ; Return -1
+
+.return:
+    ret
+
+;
+; Get a list of resistor band colors.
+;
+; Returns:
+;   rax - a list of colors
+;
+colors:
+    lea rax, [color_array]  ; Return the list of colors
+    ret
+
+%ifidn __OUTPUT_FORMAT__,elf64
+section .note.GNU-stack noalloc noexec nowrite progbits
+%endif

exercises/practice/resistor-color-duo/.meta/tests.toml

@@ -0,0 +1,31 @@
+# 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.
+
+[ce11995a-5b93-4950-a5e9-93423693b2fc]
+description = "Brown and black"
+
+[7bf82f7a-af23-48ba-a97d-38d59406a920]
+description = "Blue and grey"
+
+[f1886361-fdfd-4693-acf8-46726fe24e0c]
+description = "Yellow and violet"
+
+[b7a6cbd2-ae3c-470a-93eb-56670b305640]
+description = "White and red"
+
+[77a8293d-2a83-4016-b1af-991acc12b9fe]
+description = "Orange and orange"
+
+[0c4fb44f-db7c-4d03-afa8-054350f156a8]
+description = "Ignore additional colors"
+
+[4a8ceec5-0ab4-4904-88a4-daf953a5e818]
+description = "Black and brown, one-digit"

exercises/practice/resistor-color-duo/Makefile

@@ -0,0 +1,46 @@
+AS = nasm
+
+CFLAGS = -g -Wall -Wextra -pedantic -Werror
+LDFLAGS =
+ASFLAGS = -g -F dwarf -Werror
+
+ifeq ($(shell uname -s),Darwin)
+ifeq ($(shell sysctl -n hw.optional.arm64 2>/dev/null),1)
+	ALL_CFLAGS = -target x86_64-apple-darwin
+endif
+	ALL_LDFLAGS = -Wl,-pie -Wl,-fatal_warnings
+	ALL_ASFLAGS = -f macho64 --prefix _
+else
+	ALL_LDFLAGS = -pie -Wl,--fatal-warnings
+	ALL_ASFLAGS = -f elf64
+endif
+
+ALL_CFLAGS += -std=c99 -fPIE -m64 $(CFLAGS)
+ALL_LDFLAGS += $(LDFLAGS)
+ALL_ASFLAGS += $(ASFLAGS)
+
+C_OBJS = $(patsubst %.c,%.o,$(wildcard *.c))
+AS_OBJS = $(patsubst %.asm,%.o,$(wildcard *.asm))
+ALL_OBJS = $(filter-out example.o,$(C_OBJS) $(AS_OBJS) vendor/unity.o)
+
+CC_CMD = $(CC) $(ALL_CFLAGS) -c -o $@ $<
+
+all: tests
+	@./$<
+
+tests: $(ALL_OBJS)
+	@$(CC) $(ALL_CFLAGS) $(ALL_LDFLAGS) -o $@ $(ALL_OBJS)
+
+%.o: %.asm
+	@$(AS) $(ALL_ASFLAGS) -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/resistor-color-duo/resistor_color_duo.asm

@@ -0,0 +1,9 @@
+section .text
+global value
+value:
+    ; Provide your implementation here
+    ret
+
+%ifidn __OUTPUT_FORMAT__,elf64
+section .note.GNU-stack noalloc noexec nowrite progbits
+%endif

exercises/practice/resistor-color-duo/resistor_color_duo_test.c

@@ -0,0 +1,57 @@
+// Version: 1.0.0
+
+#include "vendor/unity.h"
+
+extern int value(const char *first, const char *second, const char *third);
+
+void setUp(void) {
+}
+
+void tearDown(void) {
+}
+
+void test_brown_and_black(void) {
+    TEST_ASSERT_EQUAL_INT(10, value("brown", "black", NULL));
+}
+
+void test_blue_and_grey(void) {
+    TEST_IGNORE();
+    TEST_ASSERT_EQUAL_INT(68, value("blue", "grey", NULL));
+}
+
+void test_yellow_and_violet(void) {
+    TEST_IGNORE();
+    TEST_ASSERT_EQUAL_INT(47, value("yellow", "violet", NULL));
+}
+
+void test_white_and_red(void) {
+    TEST_IGNORE();
+    TEST_ASSERT_EQUAL_INT(92, value("white", "red", NULL));
+}
+
+void test_orange_and_orange(void) {
+    TEST_IGNORE();
+    TEST_ASSERT_EQUAL_INT(33, value("orange", "orange", NULL));
+}
+
+void test_ignore_additional_colors(void) {
+    TEST_IGNORE();
+    TEST_ASSERT_EQUAL_INT(51, value("green", "brown", "orange"));
+}
+
+void test_black_and_brown_one_digit(void) {
+    TEST_IGNORE();
+    TEST_ASSERT_EQUAL_INT(1, value("black", "brown", NULL));
+}
+
+int main(void) {
+    UNITY_BEGIN();
+    RUN_TEST(test_brown_and_black);
+    RUN_TEST(test_blue_and_grey);
+    RUN_TEST(test_yellow_and_violet);
+    RUN_TEST(test_white_and_red);
+    RUN_TEST(test_orange_and_orange);
+    RUN_TEST(test_ignore_additional_colors);
+    RUN_TEST(test_black_and_brown_one_digit);
+    return UNITY_END();
+}