[2023] Day 1 in Zig

.gitignore

@@ -1,4 +1,5 @@
-*~
 #*#
+*~
+*.o
 __pycache__
-*.txt
+*.txt

2023/01/first.zig

@@ -0,0 +1,49 @@
+const std = @import("std");
+
+const LineIterator = struct {
+    buffer: [1024]u8 = undefined,
+    file: std.fs.File = std.io.getStdIn(),
+    pub fn next(self: *LineIterator) ?[]u8 {
+        return self.file.reader().readUntilDelimiterOrEof(&self.buffer, '\n') catch {
+            return null;
+        };
+    }
+};
+
+fn extractValue(line: []const u8) ?u8 {
+    var numbers = std.ArrayList(u8).init(std.heap.page_allocator);
+    defer numbers.deinit();
+
+    for (line) |c| {
+        if (std.ascii.isDigit(c)) {
+            numbers.append(std.fmt.charToDigit(c, 10) catch 0) catch return null;
+        }
+    }
+    return 10 * numbers.items[0] + numbers.getLast();
+}
+
+pub fn main() void {
+    var result: u32 = 0;
+    var lines = LineIterator{};
+    while (lines.next()) |line| {
+        result += extractValue(line) orelse 0;
+    }
+    std.fmt.format(std.io.getStdOut().writer(), "Sum: {}\n", .{result}) catch {};
+}
+
+test "Use the first and last digits" {
+    try std.testing.expect(extractValue("12345") == 15);
+    try std.testing.expect(extractValue("987654") == 94);
+}
+
+test "Ignore non digits" {
+    try std.testing.expect(extractValue("toto8hello5lmao2ok") == 82);
+    try std.testing.expect(extractValue("no7non4nine6nein") == 76);
+}
+
+test "Sample" {
+    try std.testing.expect(extractValue("1abc2") == 12);
+    try std.testing.expect(extractValue("pqr3stu8vwx") == 38);
+    try std.testing.expect(extractValue("a1b2c3d4e5f") == 15);
+    try std.testing.expect(extractValue("treb7uchet") == 77);
+}

2023/01/second.zig

@@ -0,0 +1,70 @@
+const std = @import("std");
+
+const LineIterator = struct {
+    buffer: [1024]u8 = undefined,
+    file: std.fs.File = std.io.getStdIn(),
+    pub fn next(self: *LineIterator) ?[]u8 {
+        return self.file.reader().readUntilDelimiterOrEof(&self.buffer, '\n') catch {
+            return null;
+        };
+    }
+};
+
+pub fn extractValue(line: []const u8) u8 {
+    const spelled = std.ComptimeStringMap(u8, .{ .{ "one", 1 }, .{ "two", 2 }, .{ "three", 3 }, .{ "four", 4 }, .{ "five", 5 }, .{ "six", 6 }, .{ "seven", 7 }, .{ "eight", 8 }, .{ "nine", 9 } });
+    var numbers = std.ArrayList(u8).init(std.heap.page_allocator);
+    defer numbers.deinit();
+
+    for (line, 0..) |c, i| {
+        if (std.fmt.charToDigit(c, 10)) |digit| {
+            numbers.append(digit) catch break;
+        } else |_| for (3..6) |length| {
+            if (length + i > line.len)
+                break;
+            if (spelled.get(line[i..][0..length])) |digit|
+                numbers.append(digit) catch break;
+        }
+    }
+    return 10 * numbers.items[0] + numbers.getLast();
+}
+
+pub fn main() void {
+    var result: u32 = 0;
+    var lines = LineIterator{};
+
+    while (lines.next()) |line| {
+        result += extractValue(line);
+    }
+    std.fmt.format(std.io.getStdOut().writer(), "Sum: {}\n", .{result}) catch {};
+}
+
+test "Still extract first and last simple digits" {
+    try std.testing.expect(extractValue("12345") == 15);
+    try std.testing.expect(extractValue("987654") == 94);
+    try std.testing.expect(extractValue("toto8hello5lmao2ok") == 82);
+    try std.testing.expect(extractValue("no7non4nine6nein") == 76);
+}
+
+test "Read numbers spelled out in letters" {
+    try std.testing.expect(extractValue("nononosix7654seven3fourmis") == 64);
+    try std.testing.expect(extractValue("wwtwo1one2eightxx") == 28);
+}
+
+test "Watch out for overlap" {
+    try std.testing.expect(extractValue("oneight") == 18);
+    try std.testing.expect(extractValue("twone") == 21);
+    try std.testing.expect(extractValue("eightwo") == 82);
+    try std.testing.expect(extractValue("threeight") == 38);
+    try std.testing.expect(extractValue("fiveight") == 58);
+    try std.testing.expect(extractValue("sevenine") == 79);
+}
+
+test "Sample" {
+    try std.testing.expect(extractValue("two1nine") == 29);
+    try std.testing.expect(extractValue("eightwothree") == 83);
+    try std.testing.expect(extractValue("abcone2threexyz") == 13);
+    try std.testing.expect(extractValue("xtwone3four") == 24);
+    try std.testing.expect(extractValue("4nineeightseven2") == 42);
+    try std.testing.expect(extractValue("zoneight234") == 14);
+    try std.testing.expect(extractValue("7pqrstsixteen") == 76);
+}

2023/01/utils.py

@@ -0,0 +1,6 @@
+def lines():
+    while True:
+        try:
+            yield input()
+        except:
+            break