Add transpose exercise

config.json

@@ -607,6 +607,14 @@
         "prerequisites": [],
         "difficulty": 4
       },
+      {
+        "slug": "transpose",
+        "name": "Transpose",
+        "uuid": "dad518d5-c579-4f7c-8a62-26b81425f173",
+        "practices": [],
+        "prerequisites": [],
+        "difficulty": 4
+      },
       {
         "slug": "yacht",
         "name": "Yacht",

exercises/practice/transpose/.docs/instructions.md

@@ -0,0 +1,61 @@
+# Instructions
+
+Given an input text output it transposed.
+
+Roughly explained, the transpose of a matrix:
+
+```text
+ABC
+DEF
+```
+
+is given by:
+
+```text
+AD
+BE
+CF
+```
+
+Rows become columns and columns become rows.
+See [transpose][].
+
+If the input has rows of different lengths, this is to be solved as follows:
+
+- Pad to the left with spaces.
+- Don't pad to the right.
+
+Therefore, transposing this matrix:
+
+```text
+ABC
+DE
+```
+
+results in:
+
+```text
+AD
+BE
+C
+```
+
+And transposing:
+
+```text
+AB
+DEF
+```
+
+results in:
+
+```text
+AD
+BE
+ F
+```
+
+In general, all characters from the input should also be present in the transposed output.
+That means that if a column in the input text contains only spaces on its bottom-most row(s), the corresponding output row should contain the spaces in its right-most column(s).
+
+[transpose]: https://en.wikipedia.org/wiki/Transpose

exercises/practice/transpose/.meta/config.json

@@ -0,0 +1,19 @@
+{
+  "authors": [
+    "keiravillekode"
+  ],
+  "files": {
+    "solution": [
+      "transpose.v"
+    ],
+    "test": [
+      "run_test.v"
+    ],
+    "example": [
+      ".meta/example.v"
+    ]
+  },
+  "blurb": "Take input text and output it transposed.",
+  "source": "Reddit r/dailyprogrammer challenge #270 [Easy].",
+  "source_url": "https://web.archive.org/web/20230630051421/https://old.reddit.com/r/dailyprogrammer/comments/4msu2x/challenge_270_easy_transpose_the_input_text/"
+}

exercises/practice/transpose/.meta/example.v

@@ -0,0 +1,31 @@
+module main
+
+import arrays
+
+fn transpose(lines []string) []string {
+	mut max_line_len := 0
+	for line in lines {
+		if max_line_len < line.len {
+			max_line_len = line.len
+		}
+	}
+
+	mut result := []string{len: max_line_len}
+	for i in 0 .. max_line_len {
+		mut buffer := []u8{cap: lines.len}
+		for j in 0 .. (lines.len) {
+			if lines[j].len <= i {
+				continue
+			}
+			for buffer.len < j {
+				buffer << ` `
+			}
+
+			buffer << lines[j][i]
+		}
+
+		result[i] = buffer.bytestr()
+	}
+
+	return result
+}

exercises/practice/transpose/.meta/tests.toml

@@ -0,0 +1,39 @@
+# 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.
+
+[404b7262-c050-4df0-a2a2-0cb06cd6a821]
+description = "empty string"
+
+[a89ce8a3-c940-4703-a688-3ea39412fbcb]
+description = "two characters in a row"
+
+[855bb6ae-4180-457c-abd0-ce489803ce98]
+description = "two characters in a column"
+
+[5ceda1c0-f940-441c-a244-0ced197769c8]
+description = "simple"
+
+[a54675dd-ae7d-4a58-a9c4-0c20e99a7c1f]
+description = "single line"
+
+[0dc2ec0b-549d-4047-aeeb-8029fec8d5c5]
+description = "first line longer than second line"
+
+[984e2ec3-b3d3-4b53-8bd6-96f5ef404102]
+description = "second line longer than first line"
+
+[eccd3784-45f0-4a3f-865a-360cb323d314]
+description = "mixed line length"
+
+[85b96b3f-d00c-4f80-8ca2-c8a5c9216c2d]
+description = "square"
+
+[b9257625-7a53-4748-8863-e08e9d27071d]
+description = "rectangle"
+
+[b80badc9-057e-4543-bd07-ce1296a1ea2c]
+description = "triangle"
+
+[76acfd50-5596-4d05-89f1-5116328a7dd9]
+description = "jagged triangle"

exercises/practice/transpose/run_test.v

@@ -0,0 +1,222 @@
+module main
+
+fn test_empty_string() {
+	lines := []string{}
+	expect := []string{}
+	assert transpose(lines) == expect
+}
+
+fn test_two_characters_in_a_row() {
+	lines := [
+		'A1',
+	]
+	expect := [
+		'A',
+		'1',
+	]
+	assert transpose(lines) == expect
+}
+
+fn test_two_characters_in_a_column() {
+	lines := [
+		'A',
+		'1',
+	]
+	expect := [
+		'A1',
+	]
+	assert transpose(lines) == expect
+}
+
+fn test_simple() {
+	lines := [
+		'ABC',
+		'123',
+	]
+	expect := [
+		'A1',
+		'B2',
+		'C3',
+	]
+	assert transpose(lines) == expect
+}
+
+fn test_single_line() {
+	lines := [
+		'Single line.',
+	]
+	expect := [
+		'S',
+		'i',
+		'n',
+		'g',
+		'l',
+		'e',
+		' ',
+		'l',
+		'i',
+		'n',
+		'e',
+		'.',
+	]
+	assert transpose(lines) == expect
+}
+
+fn test_first_line_longer_than_second_line() {
+	lines := [
+		'The fourth line.',
+		'The fifth line.',
+	]
+	expect := [
+		'TT',
+		'hh',
+		'ee',
+		'  ',
+		'ff',
+		'oi',
+		'uf',
+		'rt',
+		'th',
+		'h ',
+		' l',
+		'li',
+		'in',
+		'ne',
+		'e.',
+		'.',
+	]
+	assert transpose(lines) == expect
+}
+
+fn test_second_line_longer_than_first_line() {
+	lines := [
+		'The first line.',
+		'The second line.',
+	]
+	expect := [
+		'TT',
+		'hh',
+		'ee',
+		'  ',
+		'fs',
+		'ie',
+		'rc',
+		'so',
+		'tn',
+		' d',
+		'l ',
+		'il',
+		'ni',
+		'en',
+		'.e',
+		' .',
+	]
+	assert transpose(lines) == expect
+}
+
+fn test_mixed_line_length() {
+	lines := [
+		'The longest line.',
+		'A long line.',
+		'A longer line.',
+		'A line.',
+	]
+	expect := [
+		'TAAA',
+		'h   ',
+		'elll',
+		' ooi',
+		'lnnn',
+		'ogge',
+		'n e.',
+		'glr',
+		'ei ',
+		'snl',
+		'tei',
+		' .n',
+		'l e',
+		'i .',
+		'n',
+		'e',
+		'.',
+	]
+	assert transpose(lines) == expect
+}
+
+fn test_square() {
+	lines := [
+		'HEART',
+		'EMBER',
+		'ABUSE',
+		'RESIN',
+		'TREND',
+	]
+	expect := [
+		'HEART',
+		'EMBER',
+		'ABUSE',
+		'RESIN',
+		'TREND',
+	]
+	assert transpose(lines) == expect
+}
+
+fn test_rectangle() {
+	lines := [
+		'FRACTURE',
+		'OUTLINED',
+		'BLOOMING',
+		'SEPTETTE',
+	]
+	expect := [
+		'FOBS',
+		'RULE',
+		'ATOP',
+		'CLOT',
+		'TIME',
+		'UNIT',
+		'RENT',
+		'EDGE',
+	]
+	assert transpose(lines) == expect
+}
+
+fn test_triangle() {
+	lines := [
+		'T',
+		'EE',
+		'AAA',
+		'SSSS',
+		'EEEEE',
+		'RRRRRR',
+	]
+	expect := [
+		'TEASER',
+		' EASER',
+		'  ASER',
+		'   SER',
+		'    ER',
+		'     R',
+	]
+	assert transpose(lines) == expect
+}
+
+fn test_jagged_triangle() {
+	lines := [
+		'11',
+		'2',
+		'3333',
+		'444',
+		'555555',
+		'66666',
+	]
+	expect := [
+		'123456',
+		'1 3456',
+		'  3456',
+		'  3 56',
+		'    56',
+		'    5',
+	]
+	assert transpose(lines) == expect
+}

exercises/practice/transpose/transpose.v

@@ -0,0 +1,4 @@
+module main
+
+fn transpose(lines []string) []string {
+}