Merge pull request #43 from jimmytty/matrix

* add practice exercise: matrix

Author: jimmytty

config.json

@@ -236,6 +236,14 @@
         "prerequisites": [],
         "difficulty": 3
       },
+      {
+        "slug": "matrix",
+        "name": "Matrix",
+        "uuid": "dce69631-d5a0-4030-a7b3-3d108efdc39d",
+        "practices": [],
+        "prerequisites": [],
+        "difficulty": 3
+      },        
       {
         "slug": "line-up",
         "name": "Line Up",

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

@@ -0,0 +1,38 @@
+# Instructions
+
+Given a string representing a matrix of numbers, return the rows and columns of that matrix.
+
+So given a string with embedded newlines like:
+
+```text
+9 8 7
+5 3 2
+6 6 7
+```
+
+representing this matrix:
+
+```text
+    1  2  3
+  |---------
+1 | 9  8  7
+2 | 5  3  2
+3 | 6  6  7
+```
+
+your code should be able to spit out:
+
+- A list of the rows, reading each row left-to-right while moving top-to-bottom across the rows,
+- A list of the columns, reading each column top-to-bottom while moving from left-to-right.
+
+The rows for our example matrix:
+
+- 9, 8, 7
+- 5, 3, 2
+- 6, 6, 7
+
+And its columns:
+
+- 9, 5, 6
+- 8, 3, 6
+- 7, 2, 7

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

@@ -0,0 +1,19 @@
+{
+  "authors": [
+    "jimmytty"
+  ],
+  "files": {
+    "solution": [
+      "Matrix.pas"
+    ],
+    "test": [
+      "TestCases.pas"
+    ],
+    "example": [
+      ".meta/example.pas"
+    ]
+  },
+  "blurb": "Given a string representing a matrix of numbers, return the rows and columns of that matrix.",
+  "source": "Exercise by the JumpstartLab team for students at The Turing School of Software and Design.",
+  "source_url": "https://turing.edu"
+}

exercises/practice/matrix/.meta/example.pas

@@ -0,0 +1,60 @@
+unit Matrix;
+
+{$mode ObjFPC}{$H+}
+
+interface
+
+type
+  TIntArray  = Array Of Integer;
+  TIntMatrix = Array Of TIntArray;
+
+function row(const AString : string; const index : byte) : TIntArray;
+function column(const AString : string; const index : byte) : TIntArray;
+
+implementation
+
+uses SysUtils, StrUtils;
+
+function StringToMatrix(const AString : string) : TIntMatrix;
+var
+  LRow : string;
+  LCol : string;
+  i    : byte = 0;
+  j    : byte = 0;
+begin
+  result := [[]];
+  for LRow in SplitString(AString, '\n') do
+    begin
+      inc(i);
+      SetLength(result, i);
+      for LCol in SplitString(LRow, ' ') do
+        begin
+          insert(StrToInt(LCol), result[i - 1], j);
+          inc(j);
+        end;
+    end;
+end;
+
+function row(const AString : string; const index : byte) : TIntArray;
+var
+  LMatrix : TIntMatrix;
+  i       : byte;
+begin
+  LMatrix := StringToMatrix(AString);
+  result  := [];
+  for i := low(LMatrix[index - 1]) to high(LMatrix[index - 1]) do
+    insert(LMatrix[index - 1][i], result, i);
+end;
+
+function column(const AString : string; const index : byte) : TIntArray;
+var
+  LMatrix : TIntMatrix;
+  i       : byte;
+begin
+  LMatrix := StringToMatrix(AString);
+  result  := [];
+  for i := low(LMatrix) to high(LMatrix) do
+    insert(LMatrix[i][index - 1], result, i);
+end;
+
+end.

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

@@ -0,0 +1,34 @@
+# 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.
+
+[ca733dab-9d85-4065-9ef6-a880a951dafd]
+description = "extract row from one number matrix"
+
+[5c93ec93-80e1-4268-9fc2-63bc7d23385c]
+description = "can extract row"
+
+[2f1aad89-ad0f-4bd2-9919-99a8bff0305a]
+description = "extract row where numbers have different widths"
+
+[68f7f6ba-57e2-4e87-82d0-ad09889b5204]
+description = "can extract row from non-square matrix with no corresponding column"
+
+[e8c74391-c93b-4aed-8bfe-f3c9beb89ebb]
+description = "extract column from one number matrix"
+
+[7136bdbd-b3dc-48c4-a10c-8230976d3727]
+description = "can extract column"
+
+[ad64f8d7-bba6-4182-8adf-0c14de3d0eca]
+description = "can extract column from non-square matrix with no corresponding row"
+
+[9eddfa5c-8474-440e-ae0a-f018c2a0dd89]
+description = "extract column where numbers have different widths"

exercises/practice/matrix/Makefile

@@ -0,0 +1,15 @@
+SHELL       = /bin/bash
+MAKEFLAGS  += --no-print-directory
+DESTDIR     = build
+EXECUTABLE  = $(DESTDIR)/test
+COMMAND     = fpc -l- -v0 -g -gl -Sa -Cr -Sehnw -Fu./lib test.pas -FE"./$(DESTDIR)"
+
+.ONESHELL:
+
+test:
+	@mkdir -p "./$(DESTDIR)"
+	@cp -r ./lib "./$(DESTDIR)"
+	@$(COMMAND) && ./$(EXECUTABLE) $(test)
+
+clean:
+	@rm -fr "./$(DESTDIR)"

exercises/practice/matrix/Matrix.pas

@@ -0,0 +1,31 @@
+unit Matrix;
+
+{$mode ObjFPC}{$H+}
+
+interface
+
+type
+  TIntArray  = Array Of Integer;
+
+function row(const AString : string; const index : byte) : TIntArray;
+function column(const AString : string; const index : byte) : TIntArray;
+
+implementation
+
+uses SysUtils;
+
+function row(const AString : string; const index : byte) : TIntArray;
+begin
+
+  raise ENotImplemented.Create('Please implement your solution.'); result := [length(AString) * -1, index * -1];
+
+end;
+
+function column(const AString : string; const index : byte) : TIntArray;
+begin
+
+  raise ENotImplemented.Create('Please implement your solution.'); result := [length(AString) * -1, index * -1];
+
+end;
+
+end.

exercises/practice/matrix/TestCases.pas

@@ -0,0 +1,77 @@
+unit TestCases;
+
+{$mode ObjFPC}{$H+}
+
+interface
+
+uses Classes, SysUtils, FPCUnit, TestRegistry, FPCUnitTestUtils;
+
+type
+  MatrixTest = class(TTestCase)
+  published
+    procedure extract_row_from_one_number_matrix;
+    procedure can_extract_row;
+    procedure extract_row_where_numbers_have_different_widths;
+    procedure can_extract_row_from_non_square_matrix_with_no_corresponding_column;
+    procedure extract_column_from_one_number_matrix;
+    procedure can_extract_column;
+    procedure can_extract_column_from_non_square_matrix_with_no_corresponding_row;
+    procedure extract_column_where_numbers_have_different_widths;
+  end;
+
+implementation
+
+uses Matrix;
+
+// ca733dab-9d85-4065-9ef6-a880a951dafd
+procedure MatrixTest.extract_row_from_one_number_matrix;
+begin
+  TapAssertTrue(Self, 'extract row from one number matrix', [1], Matrix.row('1', 1));
+end;
+
+// 5c93ec93-80e1-4268-9fc2-63bc7d23385c
+procedure MatrixTest.can_extract_row;
+begin
+  TapAssertTrue(Self, 'can extract row', [3, 4], Matrix.row('1 2\n3 4', 2));
+end;
+
+// 2f1aad89-ad0f-4bd2-9919-99a8bff0305a
+procedure MatrixTest.extract_row_where_numbers_have_different_widths;
+begin
+  TapAssertTrue(Self, 'extract row where numbers have different widths', [10, 20], Matrix.row('1 2\n10 20', 2));
+end;
+
+// 68f7f6ba-57e2-4e87-82d0-ad09889b5204
+procedure MatrixTest.can_extract_row_from_non_square_matrix_with_no_corresponding_column;
+begin
+  TapAssertTrue(Self, 'can extract row from non-square matrix with no corresponding column', [8, 7, 6], Matrix.row('1 2 3\n4 5 6\n7 8 9\n8 7 6', 4));
+end;
+
+// e8c74391-c93b-4aed-8bfe-f3c9beb89ebb
+procedure MatrixTest.extract_column_from_one_number_matrix;
+begin
+  TapAssertTrue(Self, 'extract column from one number matrix', [1], Matrix.column('1', 1));
+end;
+
+// 7136bdbd-b3dc-48c4-a10c-8230976d3727
+procedure MatrixTest.can_extract_column;
+begin
+  TapAssertTrue(Self, 'can extract column', [3, 6, 9], Matrix.column('1 2 3\n4 5 6\n7 8 9', 3));
+end;
+
+// ad64f8d7-bba6-4182-8adf-0c14de3d0eca
+procedure MatrixTest.can_extract_column_from_non_square_matrix_with_no_corresponding_row;
+begin
+  TapAssertTrue(Self, 'can extract column from non-square matrix with no corresponding row', [4, 8, 6], Matrix.column('1 2 3 4\n5 6 7 8\n9 8 7 6', 4));
+end;
+
+// 9eddfa5c-8474-440e-ae0a-f018c2a0dd89
+procedure MatrixTest.extract_column_where_numbers_have_different_widths;
+begin
+  TapAssertTrue(Self, 'extract column where numbers have different widths', [1903, 3, 4], Matrix.column('89 1903 3\n18 3 1\n9 4 800', 2));
+end;
+
+initialization
+RegisterTest(MatrixTest);
+
+end.