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-rw-r--r--aoc24/src/day1.zig70
-rw-r--r--aoc24/src/day1p1.zig49
-rw-r--r--aoc24/src/day1p2.zig51
-rw-r--r--aoc24/src/day2.zig (renamed from aoc24/src/day2p2.zig)68
-rw-r--r--aoc24/src/day2p1.zig54
5 files changed, 125 insertions, 167 deletions
diff --git a/aoc24/src/day1.zig b/aoc24/src/day1.zig
new file mode 100644
index 0000000..1f26943
--- /dev/null
+++ b/aoc24/src/day1.zig
@@ -0,0 +1,70 @@
+const std = @import("std");
+
+test {
+ std.debug.assert(try part1(
+ \\3 4
+ \\4 3
+ \\2 5
+ \\1 3
+ \\3 9
+ \\3 3
+ ) == 11);
+}
+
+const Input = struct {
+ lefts: std.ArrayList(u32),
+ rights: std.ArrayList(u32),
+};
+
+pub fn parse(allocator: std.mem.Allocator, input: []const u8) !Input {
+ var lines = std.mem.split(u8, input, "\n");
+
+ var lefts = std.ArrayList(u32).init(allocator);
+ // defer lefts.deinit();
+ var rights = std.ArrayList(u32).init(allocator);
+ // defer rights.deinit();
+
+ while (lines.next()) |line| {
+ if (line.len == 0) continue;
+ var words = std.mem.split(u8, line, " ");
+ const left = try std.fmt.parseInt(u32, words.next() orelse return error.InvalidInput, 10);
+ const right = try std.fmt.parseInt(u32, words.next() orelse return error.InvalidInput, 10);
+ try lefts.append(left);
+ try rights.append(right);
+ }
+
+ return .{ .lefts = lefts, .rights = rights };
+}
+
+pub fn part1(_: std.mem.Allocator, input: Input) !u32 {
+ std.mem.sort(u32, input.lefts.items, {}, std.sort.asc(u32));
+ std.mem.sort(u32, input.rights.items, {}, std.sort.asc(u32));
+
+ var sum: u32 = 0;
+ for (input.lefts.items, input.rights.items) |l, r| {
+ sum += @max(l, r) - @min(l, r);
+ }
+
+ return sum;
+}
+
+pub fn part2(allocator: std.mem.Allocator, input: Input) !u32 {
+ var right_counts = std.AutoHashMap(u32, u16).init(allocator);
+ defer right_counts.deinit();
+
+ for (input.rights.items) |right| {
+ const entry = try right_counts.getOrPut(right);
+ if (entry.found_existing)
+ entry.value_ptr.* += 1
+ else
+ entry.value_ptr.* = 1;
+ }
+
+ var sum: u32 = 0;
+ for (input.lefts.items) |x| {
+ const count: u32 = @intCast(right_counts.get(x) orelse 0);
+ sum += x * count;
+ }
+
+ return sum;
+}
diff --git a/aoc24/src/day1p1.zig b/aoc24/src/day1p1.zig
deleted file mode 100644
index fba4b8c..0000000
--- a/aoc24/src/day1p1.zig
+++ /dev/null
@@ -1,49 +0,0 @@
-const std = @import("std");
-
-pub fn main() !void {
- const input = @embedFile("1.txt");
- try std.fmt.format(std.io.getStdOut().writer(), "{}\n", .{try run(input)});
-}
-
-test {
- std.debug.assert(try run(
- \\3 4
- \\4 3
- \\2 5
- \\1 3
- \\3 9
- \\3 3
- ) == 11);
-}
-
-pub fn run(input: []const u8) !u32 {
- var lines = std.mem.split(u8, input, "\n");
-
- var arena = std.heap.ArenaAllocator.init(std.heap.page_allocator);
- defer arena.deinit();
- const allocator = arena.allocator();
-
- var lefts = std.ArrayList(u32).init(allocator);
- defer lefts.deinit();
- var rights = std.ArrayList(u32).init(allocator);
- defer rights.deinit();
-
- while (lines.next()) |line| {
- if (line.len == 0) continue;
- var words = std.mem.split(u8, line, " ");
- const left = try std.fmt.parseInt(u32, words.next() orelse return error.InvalidInput, 10);
- const right = try std.fmt.parseInt(u32, words.next() orelse return error.InvalidInput, 10);
- try lefts.append(left);
- try rights.append(right);
- }
-
- std.mem.sort(u32, lefts.items, {}, std.sort.asc(u32));
- std.mem.sort(u32, rights.items, {}, std.sort.asc(u32));
-
- var sum: u32 = 0;
- for (lefts.items, rights.items) |l, r| {
- sum += @max(l, r) - @min(l, r);
- }
-
- return sum;
-}
diff --git a/aoc24/src/day1p2.zig b/aoc24/src/day1p2.zig
deleted file mode 100644
index 91b99fa..0000000
--- a/aoc24/src/day1p2.zig
+++ /dev/null
@@ -1,51 +0,0 @@
-const std = @import("std");
-
-pub fn main() !void {
- const input = @embedFile("1.txt");
- try std.fmt.format(std.io.getStdOut().writer(), "{}\n", .{try run(input)});
-}
-
-test {
- std.debug.assert(try run(
- \\3 4
- \\4 3
- \\2 5
- \\1 3
- \\3 9
- \\3 3
- ) == 31);
-}
-
-pub fn run(input: []const u8) !u32 {
- var lines = std.mem.split(u8, input, "\n");
-
- var arena = std.heap.ArenaAllocator.init(std.heap.page_allocator);
- defer arena.deinit();
- const allocator = arena.allocator();
-
- var lefts = std.ArrayList(u32).init(allocator);
- defer lefts.deinit();
- var rights = std.AutoHashMap(u32, u16).init(allocator);
- defer rights.deinit();
-
- while (lines.next()) |line| {
- if (line.len == 0) continue;
- var words = std.mem.split(u8, line, " ");
- const left = try std.fmt.parseInt(u32, words.next() orelse return error.InvalidInput, 10);
- const right = try std.fmt.parseInt(u32, words.next() orelse return error.InvalidInput, 10);
- try lefts.append(left);
- const entry = try rights.getOrPut(right);
- if (entry.found_existing)
- entry.value_ptr.* += 1
- else
- entry.value_ptr.* = 1;
- }
-
- var sum: u32 = 0;
- for (lefts.items) |x| {
- const count: u32 = @intCast(rights.get(x) orelse 0);
- sum += x * count;
- }
-
- return sum;
-}
diff --git a/aoc24/src/day2p2.zig b/aoc24/src/day2.zig
index fd2f7a3..656fd41 100644
--- a/aoc24/src/day2p2.zig
+++ b/aoc24/src/day2.zig
@@ -1,12 +1,28 @@
const std = @import("std");
-pub fn main() !void {
- const input = @embedFile("2.txt");
- try std.fmt.format(std.io.getStdOut().writer(), "{}\n", .{try run(input)});
+test "part 1" {
+ var arena = std.heap.ArenaAllocator.init(std.testing.allocator);
+ defer arena.deinit();
+ const allocator = arena.allocator();
+ const input = try parse(allocator,
+ \\7 6 4 2 1
+ \\1 2 7 8 9
+ \\9 7 6 2 1
+ \\1 3 2 4 5
+ \\8 6 4 4 1
+ \\1 3 6 7 9
+ );
+ const value = try part1(allocator, input);
+ const ok = value == 2;
+ if (!ok) std.debug.print("got {}\n", .{value});
+ std.debug.assert(ok);
}
-test {
- const value = try run(
+test "part 2" {
+ var arena = std.heap.ArenaAllocator.init(std.testing.allocator);
+ defer arena.deinit();
+ const allocator = arena.allocator();
+ const input = try parse(allocator,
\\7 6 4 2 1
\\1 2 7 8 9
\\9 7 6 2 1
@@ -14,19 +30,19 @@ test {
\\8 6 4 4 1
\\1 3 6 7 9
);
- std.debug.print("got {}\n", .{value});
- std.debug.assert(value == 4);
+ const value = try part2(allocator, input);
+ const ok = value == 4;
+ if (!ok) std.debug.print("got {}\n", .{value});
+ std.debug.assert(ok);
}
-pub fn run(input: []const u8) !u32 {
+pub fn parse(
+ allocator: std.mem.Allocator,
+ input: []const u8,
+) !std.ArrayList(std.ArrayList(u32)) {
var lines = std.mem.split(u8, input, "\n");
- var arena = std.heap.ArenaAllocator.init(std.heap.page_allocator);
- defer arena.deinit();
- const allocator = arena.allocator();
-
var reports = std.ArrayList(std.ArrayList(u32)).init(allocator);
- defer reports.deinit();
while (lines.next()) |line| {
if (line.len == 0) continue;
@@ -38,6 +54,32 @@ pub fn run(input: []const u8) !u32 {
try reports.append(report);
}
+ return reports;
+}
+
+pub fn part1(
+ _: std.mem.Allocator,
+ reports: std.ArrayList(std.ArrayList(u32)),
+) !u32 {
+ var safe: u32 = 0;
+ for (reports.items) |report| {
+ const increasing = report.items[0] < report.items[1];
+ for (report.items[0 .. report.items.len - 1], report.items[1..]) |prev, curr| {
+ if ((prev < curr) != increasing) break;
+ if (prev == curr) break;
+ if (@max(prev, curr) - @min(prev, curr) > 3) break;
+ } else {
+ safe += 1;
+ }
+ }
+
+ return safe;
+}
+
+pub fn part2(
+ _: std.mem.Allocator,
+ reports: std.ArrayList(std.ArrayList(u32)),
+) !u32 {
var safe: u32 = 0;
for (reports.items) |report| {
var is_safe = false;
diff --git a/aoc24/src/day2p1.zig b/aoc24/src/day2p1.zig
deleted file mode 100644
index f5263be..0000000
--- a/aoc24/src/day2p1.zig
+++ /dev/null
@@ -1,54 +0,0 @@
-const std = @import("std");
-
-pub fn main() !void {
- const input = @embedFile("2.txt");
- try std.fmt.format(std.io.getStdOut().writer(), "{}\n", .{try run(input)});
-}
-
-test {
- const value = try run(
- \\7 6 4 2 1
- \\1 2 7 8 9
- \\9 7 6 2 1
- \\1 3 2 4 5
- \\8 6 4 4 1
- \\1 3 6 7 9
- );
- std.debug.print("got {}\n", .{value});
- std.debug.assert(value == 2);
-}
-
-pub fn run(input: []const u8) !u32 {
- var lines = std.mem.split(u8, input, "\n");
-
- var arena = std.heap.ArenaAllocator.init(std.heap.page_allocator);
- defer arena.deinit();
- const allocator = arena.allocator();
-
- var reports = std.ArrayList(std.ArrayList(u32)).init(allocator);
- defer reports.deinit();
-
- while (lines.next()) |line| {
- if (line.len == 0) continue;
- var report = std.ArrayList(u32).init(allocator);
- var words = std.mem.split(u8, line, " ");
- while (words.next()) |word| {
- try report.append(try std.fmt.parseInt(u32, word, 10));
- }
- try reports.append(report);
- }
-
- var safe: u32 = 0;
- for (reports.items) |report| {
- const increasing = report.items[0] < report.items[1];
- for (report.items[0 .. report.items.len - 1], report.items[1..]) |prev, curr| {
- if ((prev < curr) != increasing) break;
- if (prev == curr) break;
- if (@max(prev, curr) - @min(prev, curr) > 3) break;
- } else {
- safe += 1;
- }
- }
-
- return safe;
-}
generated by cgit v1.2.3 (git 2.25.1) at 2025-09-10 18:52:52 +0000