feat: add practice exercise spiral-matrix (#807)

Author: ahans

config.json

@@ -999,9 +999,9 @@
         "name": "Linked List ",
         "uuid": "6f6c55dd-db6b-40ca-96f2-d9b7232dcbb0",
         "practices": [],
-        "prerequisites":[],
+        "prerequisites": [],
         "difficulty": 6,
-        "topics": [ 
+        "topics": [
           "classes",
           "conditionals",
           "loops",
@@ -1160,6 +1160,14 @@
         "practices": [],
         "prerequisites": [],
         "difficulty": 3
+      },
+      {
+        "slug": "spiral-matrix",
+        "name": "Spiral Matrix",
+        "uuid": "d5569902-5815-4b05-ab13-13826fef7826",
+        "practices": [],
+        "prerequisites": [],
+        "difficulty": 5
       }
     ],
     "foregone": [

exercises/practice/spiral-matrix/.docs/instructions.md

@@ -0,0 +1,24 @@
+# Instructions
+
+Given the size, return a square matrix of numbers in spiral order.
+
+The matrix should be filled with natural numbers, starting from 1 in the top-left corner, increasing in an inward, clockwise spiral order, like these examples:
+
+## Examples
+
+### Spiral matrix of size 3
+
+```text
+1 2 3
+8 9 4
+7 6 5
+```
+
+### Spiral matrix of size 4
+
+```text
+ 1  2  3 4
+12 13 14 5
+11 16 15 6
+10  9  8 7
+```

exercises/practice/spiral-matrix/.meta/config.json

@@ -0,0 +1,21 @@
+{
+  "authors": [
+    "ahans"
+  ],
+  "files": {
+    "solution": [
+      "spiral_matrix.cpp",
+      "spiral_matrix.h"
+    ],
+    "test": [
+      "spiral_matrix_test.cpp"
+    ],
+    "example": [
+      ".meta/example.cpp",
+      ".meta/example.h"
+    ]
+  },
+  "blurb": "Given the size, return a square matrix of numbers in spiral order.",
+  "source": "Reddit r/dailyprogrammer challenge #320 [Easy] Spiral Ascension.",
+  "source_url": "https://web.archive.org/web/20230607064729/https://old.reddit.com/r/dailyprogrammer/comments/6i60lr/20170619_challenge_320_easy_spiral_ascension/"
+}

exercises/practice/spiral-matrix/.meta/example.cpp

@@ -0,0 +1,53 @@
+#include <tuple>
+
+#include "spiral_matrix.h"
+
+namespace spiral_matrix {
+
+namespace {
+
+using Coords = std::tuple<int32_t, int32_t>;
+using Dir = std::tuple<int32_t, int32_t>;
+
+[[nodiscard]] Coords operator+(Coords const coords, Dir const dir) {
+    auto const [row, col] = coords;
+    auto const [dr, dc] = dir;
+    return {row + dr, col + dc};
+}
+
+}  // namespace
+
+std::vector<std::vector<uint32_t>> spiral_matrix(uint32_t const size) {
+    std::vector<std::vector<uint32_t>> matrix(size,
+                                              std::vector<uint32_t>(size));
+
+    constexpr auto rotate_clockwise = [](Dir const dir) {
+        auto const [dr, dc] = dir;
+        return Dir{dc, -dr};
+    };
+
+    auto const matrix_elem = [&matrix](Coords coords) -> auto& {
+        auto const [row, col] = coords;
+        return matrix[row][col];
+    };
+
+    auto const in_bounds = [size](Coords const coords) {
+        auto const [row, col] = coords;
+        return 0 <= row && row < static_cast<int32_t>(size) && 0 <= col &&
+               col < static_cast<int32_t>(size);
+    };
+
+    Coords coords{};
+    Dir dir{0, 1};
+    for (uint32_t i = 1; i <= size * size; ++i) {
+        matrix_elem(coords) = i;
+        if (!in_bounds(coords + dir) || matrix_elem(coords + dir) != 0) {
+            dir = rotate_clockwise(dir);
+        }
+        coords = coords + dir;
+    }
+
+    return matrix;
+}
+
+}  // namespace spiral_matrix

exercises/practice/spiral-matrix/.meta/example.h

@@ -0,0 +1,13 @@
+#if !defined(SPIRAL_MATRIX_H)
+#define SPIRAL_MATRIX_H
+
+#include <cstdint>
+#include <vector>
+
+namespace spiral_matrix {
+
+[[nodiscard]] std::vector<std::vector<uint32_t>> spiral_matrix(uint32_t size);
+
+}  // namespace spiral_matrix
+
+#endif  // SPIRAL_MATRIX_H

exercises/practice/spiral-matrix/.meta/tests.toml

@@ -0,0 +1,28 @@
+# 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.
+
+[8f584201-b446-4bc9-b132-811c8edd9040]
+description = "empty spiral"
+
+[e40ae5f3-e2c9-4639-8116-8a119d632ab2]
+description = "trivial spiral"
+
+[cf05e42d-eb78-4098-a36e-cdaf0991bc48]
+description = "spiral of size 2"
+
+[1c475667-c896-4c23-82e2-e033929de939]
+description = "spiral of size 3"
+
+[05ccbc48-d891-44f5-9137-f4ce462a759d]
+description = "spiral of size 4"
+
+[f4d2165b-1738-4e0c-bed0-c459045ae50d]
+description = "spiral of size 5"

exercises/practice/spiral-matrix/CMakeLists.txt

@@ -0,0 +1,64 @@
+# Get the exercise name from the current directory
+get_filename_component(exercise ${CMAKE_CURRENT_SOURCE_DIR} NAME)
+
+# Basic CMake project
+cmake_minimum_required(VERSION 3.5.1)
+
+# Name the project after the exercise
+project(${exercise} CXX)
+
+# Get a source filename from the exercise name by replacing -'s with _'s
+string(REPLACE "-" "_" file ${exercise})
+
+# Implementation could be only a header
+if(EXISTS ${CMAKE_CURRENT_SOURCE_DIR}/${file}.cpp)
+    set(exercise_cpp ${file}.cpp)
+else()
+    set(exercise_cpp "")
+endif()
+
+# Use the common Catch library?
+if(EXERCISM_COMMON_CATCH)
+    # For Exercism track development only
+    add_executable(${exercise} ${file}_test.cpp ${exercise_cpp} ${file}.h $<TARGET_OBJECTS:catchlib>)
+elseif(EXERCISM_TEST_SUITE)
+    # The Exercism test suite is being run, the Docker image already
+    # includes a pre-built version of Catch.
+    find_package(Catch2 REQUIRED)
+    add_executable(${exercise} ${file}_test.cpp ${exercise_cpp} ${file}.h)
+    target_link_libraries(${exercise} PRIVATE Catch2::Catch2WithMain)
+    # When Catch is installed system wide we need to include a different
+    # header, we need this define to use the correct one.
+    target_compile_definitions(${exercise} PRIVATE EXERCISM_TEST_SUITE)
+else()
+    # Build executable from sources and headers
+    add_executable(${exercise} ${file}_test.cpp ${exercise_cpp} ${file}.h test/tests-main.cpp)
+endif()
+
+set_target_properties(${exercise} PROPERTIES
+    CXX_STANDARD 17
+    CXX_STANDARD_REQUIRED OFF
+    CXX_EXTENSIONS OFF
+)
+
+set(CMAKE_BUILD_TYPE Debug)
+
+if("${CMAKE_CXX_COMPILER_ID}" MATCHES "(GNU|Clang)")
+    set_target_properties(${exercise} PROPERTIES
+        COMPILE_FLAGS "-Wall -Wextra -Wpedantic -Werror"
+    )
+endif()
+
+# Configure to run all the tests?
+if(${EXERCISM_RUN_ALL_TESTS})
+    target_compile_definitions(${exercise} PRIVATE EXERCISM_RUN_ALL_TESTS)
+endif()
+
+# Tell MSVC not to warn us about unchecked iterators in debug builds
+if(${MSVC})
+    set_target_properties(${exercise} PROPERTIES
+        COMPILE_DEFINITIONS_DEBUG _SCL_SECURE_NO_WARNINGS)
+endif()
+
+# Run the tests on every build
+add_custom_target(test_${exercise} ALL DEPENDS ${exercise} COMMAND ${exercise})

exercises/practice/spiral-matrix/spiral_matrix.cpp

@@ -0,0 +1,5 @@
+#include "spiral_matrix.h"
+
+namespace spiral_matrix {
+
+}  // namespace spiral_matrix

exercises/practice/spiral-matrix/spiral_matrix.h

@@ -0,0 +1,8 @@
+#if !defined(SPIRAL_MATRIX_H)
+#define SPIRAL_MATRIX_H
+
+namespace spiral_matrix {
+
+}  // namespace spiral_matrix
+
+#endif  // SPIRAL_MATRIX_H

exercises/practice/spiral-matrix/spiral_matrix_test.cpp

@@ -0,0 +1,60 @@
+#include "spiral_matrix.h"
+
+#ifdef EXERCISM_TEST_SUITE
+#include <catch2/catch.hpp>
+#else
+#include "test/catch.hpp"
+#endif
+
+#include <cstdint>
+#include <vector>
+
+TEST_CASE("empty spiral", "[8f584201-b446-4bc9-b132-811c8edd9040]") {
+    std::vector<std::vector<uint32_t>> const expected{};
+    REQUIRE(expected == spiral_matrix::spiral_matrix(0));
+}
+
+#if defined(EXERCISM_RUN_ALL_TESTS)
+TEST_CASE("trivial spiral", "[e40ae5f3-e2c9-4639-8116-8a119d632ab2]") {
+    std::vector<std::vector<uint32_t>> const expected = {{1}};
+    REQUIRE(expected == spiral_matrix::spiral_matrix(1));
+}
+
+TEST_CASE("spiral of size 2", "[cf05e42d-eb78-4098-a36e-cdaf0991bc48]") {
+    std::vector<std::vector<uint32_t>> const expected = {
+        {1, 2},  //
+        {4, 3}   //
+    };
+    REQUIRE(expected == spiral_matrix::spiral_matrix(2));
+}
+
+TEST_CASE("spiral of size 3", "[1c475667-c896-4c23-82e2-e033929de939]") {
+    std::vector<std::vector<uint32_t>> expected = {
+        {1, 2, 3},  //
+        {8, 9, 4},  //
+        {7, 6, 5}   //
+    };
+    REQUIRE(expected == spiral_matrix::spiral_matrix(3));
+}
+
+TEST_CASE("spiral of size 4", "[05ccbc48-d891-44f5-9137-f4ce462a759d]") {
+    std::vector<std::vector<uint32_t>> const expected = {
+        {1, 2, 3, 4},     //
+        {12, 13, 14, 5},  //
+        {11, 16, 15, 6},  //
+        {10, 9, 8, 7}     //
+    };
+    REQUIRE(expected == spiral_matrix::spiral_matrix(4));
+}
+
+TEST_CASE("spiral of size 5", "[f4d2165b-1738-4e0c-bed0-c459045ae50d]") {
+    std::vector<std::vector<uint32_t>> const expected = {
+        {1, 2, 3, 4, 5},      //
+        {16, 17, 18, 19, 6},  //
+        {15, 24, 25, 20, 7},  //
+        {14, 23, 22, 21, 8},  //
+        {13, 12, 11, 10, 9}   //
+    };
+    REQUIRE(expected == spiral_matrix::spiral_matrix(5));
+}
+#endif