Zig: completed Collatz Conjecture and Isogram

zig/collatz-conjecture/.exercism/config.json

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+{
+  "authors": [
+    "massivelivefun"
+  ],
+  "contributors": [
+    "ee7"
+  ],
+  "files": {
+    "solution": [
+      "collatz_conjecture.zig"
+    ],
+    "test": [
+      "test_collatz_conjecture.zig"
+    ],
+    "example": [
+      ".meta/example.zig"
+    ]
+  },
+  "blurb": "Calculate the number of steps to reach 1 using the Collatz conjecture.",
+  "source": "An unsolved problem in mathematics named after mathematician Lothar Collatz",
+  "source_url": "https://en.wikipedia.org/wiki/3x_%2B_1_problem"
+}

zig/collatz-conjecture/.exercism/metadata.json

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+{"track":"zig","exercise":"collatz-conjecture","id":"246eebc2ac2e4981be47574fc2b1b0cf","url":"https://exercism.org/tracks/zig/exercises/collatz-conjecture","handle":"Chomp1295","is_requester":true,"auto_approve":false}

zig/collatz-conjecture/HELP.md

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+# Help
+
+## Running the tests
+
+Write your code in `<exercise_name>.zig`.
+
+To run the tests for an exercise, run:
+
+```bash
+zig test test_exercise_name.zig
+```
+
+in the exercise's root directory (replacing `exercise_name` with the name of the exercise).
+
+## Submitting your solution
+
+You can submit your solution using the `exercism submit collatz_conjecture.zig` command.
+This command will upload your solution to the Exercism website and print the solution page's URL.
+
+It's possible to submit an incomplete solution which allows you to:
+
+- See how others have completed the exercise
+- Request help from a mentor
+
+## Need to get help?
+
+If you'd like help solving the exercise, check the following pages:
+
+- The [Zig track's documentation](https://exercism.org/docs/tracks/zig)
+- The [Zig track's programming category on the forum](https://forum.exercism.org/c/programming/zig)
+- [Exercism's programming category on the forum](https://forum.exercism.org/c/programming/5)
+- The [Frequently Asked Questions](https://exercism.org/docs/using/faqs)
+
+Should those resources not suffice, you could submit your (incomplete) solution to request mentoring.
+
+- [The Zig Programming Language Documentation][documentation] is a great overview of all of the language features that Zig provides to those who use it.
+- [Zig Guide][zig-guide] is an excellent primer that explains the language features that Zig has to offer.
+- [Ziglings][ziglings] is highly recommended.
+  Learn Zig by fixing tiny broken programs.
+- [The Zig Programming Language Discord][discord-zig] is the main [Discord][discord].
+  It provides a great way to get in touch with the Zig community at large, and get some quick, direct help for any Zig related problem.
+- [#zig][irc] on irc.freenode.net is the main Zig IRC channel.
+- [/r/Zig][reddit] is the main Zig subreddit.
+- [Stack Overflow][stack-overflow] can be used to discover code snippets and solutions to problems that may have already asked and maybe solved by others.
+
+[discord]: https://discordapp.com
+[discord-zig]: https://discord.com/invite/gxsFFjE
+[documentation]: https://ziglang.org/documentation/master
+[irc]: https://webchat.freenode.net/?channels=%23zig
+[reddit]: https://www.reddit.com/r/Zig
+[stack-overflow]: https://stackoverflow.com/questions/tagged/zig
+[zig-guide]: https://zig.guide/
+[ziglings]: https://codeberg.org/ziglings/exercises

zig/collatz-conjecture/README.md

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+# Collatz Conjecture
+
+Welcome to Collatz Conjecture on Exercism's Zig Track.
+If you need help running the tests or submitting your code, check out `HELP.md`.
+
+## Instructions
+
+The Collatz Conjecture or 3x+1 problem can be summarized as follows:
+
+Take any positive integer n.
+If n is even, divide n by 2 to get n / 2.
+If n is odd, multiply n by 3 and add 1 to get 3n + 1.
+Repeat the process indefinitely.
+The conjecture states that no matter which number you start with, you will always reach 1 eventually.
+
+Given a number n, return the number of steps required to reach 1.
+
+## Examples
+
+Starting with n = 12, the steps would be as follows:
+
+0. 12
+1. 6
+2. 3
+3. 10
+4. 5
+5. 16
+6. 8
+7. 4
+8. 2
+9. 1
+
+Resulting in 9 steps.
+So for input n = 12, the return value would be 9.
+
+## Error handling
+
+For this exercise you must add an error set `ComputationError` that contains the `IllegalArgument` error.
+Remember to make it public!
+The `steps` function must return `ComputationError.IllegalArgument` when its input is equal to zero.
+
+Later exercises will usually omit explicit instructions like this.
+In general, Exercism expects you to read the test file when implementing your solution.
+
+For more details about errors in Zig, see:
+
+- [Learning Zig - Errors][learning-zig-errors]
+- [Ziglings - Exercise 21][ziglings-exercise-21]
+- [Zighelp - Errors][zighelp-errors]
+
+[learning-zig-errors]: https://www.openmymind.net/learning_zig/language_overview_2/#errors
+[zighelp-errors]: https://zighelp.org/chapter-1/#errors
+[ziglings-exercise-21]: https://codeberg.org/ziglings/exercises/src/commit/0d46acfa02d0c29fdfb3651e82a77284dd8f2e00/exercises/021_errors.zig
+
+## Source
+
+### Created by
+
+- @massivelivefun
+
+### Contributed to by
+
+- @ee7
+
+### Based on
+
+An unsolved problem in mathematics named after mathematician Lothar Collatz - https://en.wikipedia.org/wiki/3x_%2B_1_problem

zig/collatz-conjecture/collatz_conjecture.zig

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+// Please implement the `ComputationError.IllegalArgument` error.
+
+pub const ComputationError = error{IllegalArgument};
+
+pub fn steps(number: usize) anyerror!usize {
+    if (number < 1) return ComputationError.IllegalArgument;
+
+    var count: usize = 0;
+    var temp: usize = number;
+    while (temp > 1) : (count += 1) {
+        if (temp % 2 == 0) {
+            temp /= 2;
+        } else {
+            temp = temp * 3 + 1;
+        }
+    }
+
+    return count;
+}

zig/collatz-conjecture/test_collatz_conjecture.zig

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+const std = @import("std");
+const testing = std.testing;
+
+const collatz_conjecture = @import("collatz_conjecture.zig");
+const ComputationError = collatz_conjecture.ComputationError;
+
+test "zero steps for one" {
+    const expected: usize = 0;
+    const actual = try collatz_conjecture.steps(1);
+    try testing.expectEqual(expected, actual);
+}
+
+test "divide if even" {
+    const expected: usize = 4;
+    const actual = try collatz_conjecture.steps(16);
+    try testing.expectEqual(expected, actual);
+}
+
+test "even and odd steps" {
+    const expected: usize = 9;
+    const actual = try collatz_conjecture.steps(12);
+    try testing.expectEqual(expected, actual);
+}
+
+test "large number of even and odd steps" {
+    const expected: usize = 152;
+    const actual = try collatz_conjecture.steps(1_000_000);
+    try testing.expectEqual(expected, actual);
+}
+
+test "zero is an error" {
+    const expected = ComputationError.IllegalArgument;
+    const actual = collatz_conjecture.steps(0);
+    try testing.expectError(expected, actual);
+}

zig/isogram/.exercism/config.json

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+{
+  "authors": [
+    "massivelivefun"
+  ],
+  "files": {
+    "solution": [
+      "isogram.zig"
+    ],
+    "test": [
+      "test_isogram.zig"
+    ],
+    "example": [
+      ".meta/example.zig"
+    ]
+  },
+  "blurb": "Determine if a word or phrase is an isogram.",
+  "source": "Wikipedia",
+  "source_url": "https://en.wikipedia.org/wiki/Isogram"
+}

zig/isogram/.exercism/metadata.json

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+{"track":"zig","exercise":"isogram","id":"445c8a98e0724f5ab514881b68c8d01c","url":"https://exercism.org/tracks/zig/exercises/isogram","handle":"Chomp1295","is_requester":true,"auto_approve":false}

zig/isogram/HELP.md

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+# Help
+
+## Running the tests
+
+Write your code in `<exercise_name>.zig`.
+
+To run the tests for an exercise, run:
+
+```bash
+zig test test_exercise_name.zig
+```
+
+in the exercise's root directory (replacing `exercise_name` with the name of the exercise).
+
+## Submitting your solution
+
+You can submit your solution using the `exercism submit isogram.zig` command.
+This command will upload your solution to the Exercism website and print the solution page's URL.
+
+It's possible to submit an incomplete solution which allows you to:
+
+- See how others have completed the exercise
+- Request help from a mentor
+
+## Need to get help?
+
+If you'd like help solving the exercise, check the following pages:
+
+- The [Zig track's documentation](https://exercism.org/docs/tracks/zig)
+- The [Zig track's programming category on the forum](https://forum.exercism.org/c/programming/zig)
+- [Exercism's programming category on the forum](https://forum.exercism.org/c/programming/5)
+- The [Frequently Asked Questions](https://exercism.org/docs/using/faqs)
+
+Should those resources not suffice, you could submit your (incomplete) solution to request mentoring.
+
+- [The Zig Programming Language Documentation][documentation] is a great overview of all of the language features that Zig provides to those who use it.
+- [Zig Guide][zig-guide] is an excellent primer that explains the language features that Zig has to offer.
+- [Ziglings][ziglings] is highly recommended.
+  Learn Zig by fixing tiny broken programs.
+- [The Zig Programming Language Discord][discord-zig] is the main [Discord][discord].
+  It provides a great way to get in touch with the Zig community at large, and get some quick, direct help for any Zig related problem.
+- [#zig][irc] on irc.freenode.net is the main Zig IRC channel.
+- [/r/Zig][reddit] is the main Zig subreddit.
+- [Stack Overflow][stack-overflow] can be used to discover code snippets and solutions to problems that may have already asked and maybe solved by others.
+
+[discord]: https://discordapp.com
+[discord-zig]: https://discord.com/invite/gxsFFjE
+[documentation]: https://ziglang.org/documentation/master
+[irc]: https://webchat.freenode.net/?channels=%23zig
+[reddit]: https://www.reddit.com/r/Zig
+[stack-overflow]: https://stackoverflow.com/questions/tagged/zig
+[zig-guide]: https://zig.guide/
+[ziglings]: https://codeberg.org/ziglings/exercises

zig/isogram/README.md

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+# Isogram
+
+Welcome to Isogram on Exercism's Zig Track.
+If you need help running the tests or submitting your code, check out `HELP.md`.
+
+## Instructions
+
+Determine if a word or phrase is an isogram.
+
+An isogram (also known as a "non-pattern word") is a word or phrase without a repeating letter, however spaces and hyphens are allowed to appear multiple times.
+
+Examples of isograms:
+
+- lumberjacks
+- background
+- downstream
+- six-year-old
+
+The word _isograms_, however, is not an isogram, because the s repeats.
+
+## Source
+
+### Created by
+
+- @massivelivefun
+
+### Based on
+
+Wikipedia - https://en.wikipedia.org/wiki/Isogram

zig/isogram/isogram.zig

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+pub const std = @import("std");
+
+pub fn cmp(context: void, a: u8, b: u8) bool {
+    _ = context;
+    if (a < b) {
+        return true;
+    }
+    return false;
+}
+
+pub fn isIsogram(str: []const u8) bool {
+    const len = str.len;
+    if (len == 0) return true;
+
+    var buf = [_]u8{0} ** 256;
+    const lower = std.ascii.lowerString(&buf, str);
+    std.mem.sort(u8, lower, {}, cmp);
+
+    for (0..len - 1) |i| {
+        if (lower[i] == lower[i + 1] and std.ascii.isAlphabetic(lower[i])) {
+            return false;
+        }
+    }
+
+    return true;
+}

zig/isogram/test_isogram.zig

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+const std = @import("std");
+const testing = std.testing;
+
+const isogram = @import("isogram.zig");
+
+test "empty string" {
+    try testing.expect(isogram.isIsogram(""));
+}
+
+test "isogram with only lower case characters" {
+    try testing.expect(isogram.isIsogram("isogram"));
+}
+
+test "word with one duplicated character" {
+    try testing.expect(!isogram.isIsogram("eleven"));
+}
+
+test "word with one duplicated character from the end of the alphabet" {
+    try testing.expect(!isogram.isIsogram("zzyzx"));
+}
+
+test "longest reported english isogram" {
+    try testing.expect(isogram.isIsogram("subdermatoglyphic"));
+}
+
+test "word with duplicated character in mixed case" {
+    try testing.expect(!isogram.isIsogram("Alphabet"));
+}
+
+test "word with duplicated character in mixed case, lowercase first" {
+    try testing.expect(!isogram.isIsogram("alphAbet"));
+}
+
+test "hypothetical isogrammic word with hyphen" {
+    try testing.expect(isogram.isIsogram("thumbscrew-japingly"));
+}
+
+test "hypothetical word with duplicated character following hyphen" {
+    try testing.expect(!isogram.isIsogram("thumbscrew-jappingly"));
+}
+
+test "isogram with duplicated hyphen" {
+    try testing.expect(isogram.isIsogram("six-year-old"));
+}
+
+test "made-up name that is an isogram" {
+    try testing.expect(isogram.isIsogram("Emily Jung Schwartzkopf"));
+}
+
+test "duplicated character in the middle" {
+    try testing.expect(!isogram.isIsogram("accentor"));
+}
+
+test "same first and last characters" {
+    try testing.expect(!isogram.isIsogram("angola"));
+}
+
+test "word with duplicated character and with two hyphens" {
+    try testing.expect(!isogram.isIsogram("up-to-date"));
+}