feat: add matrix exercise (#179)

* feat: add matrix exercise

* use split_into_lines

Author: keiravillekode

config.json

@@ -601,6 +601,14 @@
         "prerequisites": [],
         "difficulty": 4
       },
+      {
+        "slug": "matrix",
+        "name": "Matrix",
+        "uuid": "b389b48c-fa60-41f6-8e5e-491b4ca7a346",
+        "practices": [],
+        "prerequisites": [],
+        "difficulty": 4
+      },
       {
         "slug": "gigasecond",
         "name": "Gigasecond",

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": [
+    "keiravillekode"
+  ],
+  "files": {
+    "solution": [
+      "matrix.v"
+    ],
+    "test": [
+      "run_test.v"
+    ],
+    "example": [
+      ".meta/example.v"
+    ]
+  },
+  "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.v

@@ -0,0 +1,15 @@
+module main
+
+fn row(str string, index int) []int {
+	line := str.split_into_lines()[index - 1]
+	return line.split(' ').map(fn (s string) int {
+		return s.int()
+	})
+}
+
+fn column(str string, index int) []int {
+	lines := str.split_into_lines()
+	return lines.map(fn [index] (line string) int {
+		return line.split(' ')[index - 1].int()
+	})
+}

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

@@ -0,0 +1,27 @@
+# This is an auto-generated file. Regular comments will be removed when this
+# file is regenerated. Regenerating will not touch any manually added keys,
+# so comments can be added in 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/matrix.v

@@ -0,0 +1,7 @@
+module main
+
+fn row(str string, index int) []int {
+}
+
+fn column(str string, index int) []int {
+}

exercises/practice/matrix/run_test.v

@@ -0,0 +1,41 @@
+module main
+
+fn test_extract_row_from_one_number_matrix() {
+	str := '1'
+	assert row(str, 1) == [1]
+}
+
+fn test_can_extract_row() {
+	str := '1 2\n3 4'
+	assert row(str, 2) == [3, 4]
+}
+
+fn test_extract_row_where_numbers_have_different_widths() {
+	str := '1 2\n10 20'
+	assert row(str, 2) == [10, 20]
+}
+
+fn test_can_extract_row_from_non_square_matrix_with_no_corresponding_column() {
+	str := '1 2 3\n4 5 6\n7 8 9\n8 7 6'
+	assert row(str, 4) == [8, 7, 6]
+}
+
+fn test_extract_column_from_one_number_matrix() {
+	str := '1'
+	assert column(str, 1) == [1]
+}
+
+fn test_can_extract_column() {
+	str := '1 2 3\n4 5 6\n7 8 9'
+	assert column(str, 3) == [3, 6, 9]
+}
+
+fn test_can_extract_column_from_non_square_matrix_with_no_corresponding_row() {
+	str := '1 2 3 4\n5 6 7 8\n9 8 7 6'
+	assert column(str, 4) == [4, 8, 6]
+}
+
+fn test_extract_column_where_numbers_have_different_widths() {
+	str := '89 1903 3\n18 3 1\n9 4 800'
+	assert column(str, 2) == [1903, 3, 4]
+}