day05 part2 OOM killed lmao

src/day05.zig

@@ -0,0 +1,171 @@
+const std = @import("std");
+const util = @import("util.zig");
+const mem = std.mem;
+
+pub fn main() !void {
+    const input = @embedFile("data/day05.txt");
+    const sln = try solve(util.gpa, input);
+    std.debug.print("{d}\n", .{sln.a});
+    std.debug.print("{d}\n", .{sln.b});
+}
+
+const Solution = struct {
+    a: usize,
+    b: usize,
+};
+
+const Transform = struct {
+    from: []const u8,
+    to: []const u8,
+};
+
+const Map = struct {
+    dest_start: usize,
+    source_start: usize,
+    range: usize,
+};
+
+const Component = struct {
+    name: []const u8,
+    value: usize,
+};
+
+fn solve(alloc: mem.Allocator, input: []const u8) !Solution {
+    var it = util.splitLines(input);
+    const seed_line = it.next().?;
+    const seeds = try util.parseIntsScalar(usize, alloc, seed_line[mem.indexOfScalar(u8, seed_line, ':').? + 1 ..], .{});
+    defer alloc.free(seeds);
+    var last_components = try std.ArrayList(Component).initCapacity(alloc, seeds.len);
+    defer last_components.deinit();
+
+    var seeds_index: usize = 0;
+    while (seeds_index < seeds.len) : (seeds_index += 2) {
+        const start = seeds[seeds_index];
+        const range = seeds[seeds_index + 1];
+        for (start..start + range) |seed| {
+            try last_components.append(.{ .name = "seed", .value = seed });
+        }
+    }
+
+    var current_component: []const u8 = undefined;
+    while (it.next()) |line| {
+        if (line.len == 0) {
+            for (last_components.items, 0..) |comp, index| {
+                if (!mem.eql(u8, comp.name, current_component)) {
+                    last_components.items[index] = .{ .name = current_component, .value = comp.value };
+                }
+            }
+        } else if (mem.endsWith(u8, line, "map:")) {
+            var t_it = util.split(line, ' ');
+            var comp_it = util.split(t_it.next().?, '-');
+            _ = comp_it.next(); // A
+            _ = comp_it.next(); // to
+            current_component = comp_it.next().?; // B
+        } else {
+            const map = try util.parseIntsScalar(usize, alloc, line, .{});
+            defer alloc.free(map);
+            // map values
+            map_blk: for (last_components.items, 0..) |comp, index| {
+                if (mem.eql(u8, comp.name, current_component)) {
+                    std.debug.print("{d} already mapped\n", .{index});
+                    continue :map_blk;
+                }
+                if (map[1] <= comp.value and comp.value <= map[1] + map[2]) {
+                    const offset = @as(isize, @intCast(map[0])) - @as(isize, @intCast(map[1]));
+                    const res: usize = @intCast(@as(isize, @intCast(comp.value)) + offset);
+                    std.debug.print("{d} {d} => {d}\n", .{ index, comp.value, res });
+                    last_components.items[index] = .{ .name = current_component, .value = res };
+                }
+            }
+        }
+    }
+
+    var low_loc: usize = std.math.maxInt(usize);
+    for (last_components.items) |comp| {
+        std.debug.print("{s} ", .{comp.name});
+        low_loc = @min(low_loc, comp.value);
+    }
+
+    return .{ .a = low_loc, .b = 0 };
+}
+
+test "silver" {
+    const input =
+        \\seeds: 79 14 55 13
+        \\
+        \\seed-to-soil map:
+        \\50 98 2
+        \\52 50 48
+        \\
+        \\soil-to-fertilizer map:
+        \\0 15 37
+        \\37 52 2
+        \\39 0 15
+        \\
+        \\fertilizer-to-water map:
+        \\49 53 8
+        \\0 11 42
+        \\42 0 7
+        \\57 7 4
+        \\
+        \\water-to-light map:
+        \\88 18 7
+        \\18 25 70
+        \\
+        \\light-to-temperature map:
+        \\45 77 23
+        \\81 45 19
+        \\68 64 13
+        \\
+        \\temperature-to-humidity map:
+        \\0 69 1
+        \\1 0 69
+        \\
+        \\humidity-to-location map:
+        \\60 56 37
+        \\56 93 4
+    ;
+    _ = input;
+    // const sln = try solve(std.testing.allocator, input);
+    // try std.testing.expectEqual(@as(usize, 35), sln.a);
+}
+
+test "gold" {
+    const input =
+        \\seeds: 79 14 55 13
+        \\
+        \\seed-to-soil map:
+        \\50 98 2
+        \\52 50 48
+        \\
+        \\soil-to-fertilizer map:
+        \\0 15 37
+        \\37 52 2
+        \\39 0 15
+        \\
+        \\fertilizer-to-water map:
+        \\49 53 8
+        \\0 11 42
+        \\42 0 7
+        \\57 7 4
+        \\
+        \\water-to-light map:
+        \\88 18 7
+        \\18 25 70
+        \\
+        \\light-to-temperature map:
+        \\45 77 23
+        \\81 45 19
+        \\68 64 13
+        \\
+        \\temperature-to-humidity map:
+        \\0 69 1
+        \\1 0 69
+        \\
+        \\humidity-to-location map:
+        \\60 56 37
+        \\56 93 4
+    ;
+    const sln = try solve(std.testing.allocator, input);
+    try std.testing.expectEqual(@as(usize, 46), sln.a);
+}