1
0

hey lmao day05

This commit is contained in:
xeals 2023-12-06 11:17:05 +11:00
parent faf81869d6
commit 0f2044b762
Signed by: xeals
SSH Key Fingerprint: SHA256:pRv+8swQDA+/LuZ7NHj9m006BbKexlNK62OUA01ZZBc

View File

@ -5,117 +5,179 @@ 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});
std.debug.print("{d}\n", .{sln});
std.debug.print("{d}\n", .{sln});
}
const Solution = struct {
a: usize,
b: usize,
};
fn Range(comptime T: type) type {
return struct {
start: T,
end: T,
const Transform = struct {
from: []const u8,
to: []const u8,
};
const Self = @This();
/// Returns the intersection of two ranges.
pub fn intersect(self: Self, other: Self) ?Self {
const a = if (self.start < other.start) self else other;
const b = if (self.start < other.start) other else self;
// std.debug.print("{any}/{any}\n", .{ a, b });
if (a.start == a.end or b.start == b.end) return null; // Points don't intersect.
if (a.end < b.start) return null; // No intersection.
if (a.end > b.end) return b; // A is a superset of B.
return .{ .start = b.start, .end = a.end };
}
/// Returns the union of two ranges.
pub fn join(self: Self, other: Self) ?Self {
if (self.intersect(other) == null) return null; // Can't union disjoint ranges.
// std.debug.print("merge {any}+{any}\n", .{ self, other });
// Now guaranteed that they overlap.
const merged = Self{ .start = @min(self.start, other.start), .end = @max(self.end, other.end) };
std.debug.print("= {any}\n", .{merged});
return merged;
}
};
}
test "range intersect" {
const R = Range(usize);
const e = .{ .start = 2, .end = 5 };
// Superset
try std.testing.expectEqual(e, (R{ .start = 0, .end = 6 }).intersect(.{ .start = 2, .end = 5 }));
try std.testing.expectEqual(e, (R{ .start = 2, .end = 5 }).intersect(.{ .start = 0, .end = 6 }));
// A < B
try std.testing.expectEqual(e, (R{ .start = 0, .end = 5 }).intersect(.{ .start = 2, .end = 6 }));
// B < A
try std.testing.expectEqual(e, (R{ .start = 2, .end = 6 }).intersect(.{ .start = 0, .end = 5 }));
// No intersect
try std.testing.expect(null == (R{ .start = 0, .end = 3 }).intersect(.{ .start = 4, .end = 6 }));
}
const Map = struct {
dest_start: usize,
source_start: usize,
range: usize,
offset: isize,
source: Range(usize),
};
const Component = struct {
name: []const u8,
value: usize,
stage: usize,
range: Range(usize),
};
const UsizeSet = std.AutoHashMap(usize, void);
fn mergeRanges(ranges: *std.ArrayList(Component)) void {
var i: usize = 0;
while (i < ranges.items.len) : (i += 1) {
var item = ranges.items[i];
var j = i + 1;
while (j < ranges.items.len) {
const next = ranges.items[j];
if (item.range.join(next.range)) |merged| {
const merged_item = .{ .stage = item.stage, .range = merged };
item = merged_item;
ranges.items[i] = merged_item;
_ = ranges.swapRemove(j);
} else {
j += 1;
}
}
}
}
fn solve(alloc: mem.Allocator, input: []const u8) !Solution {
test "mergeRanges" {
var ranges = std.ArrayList(Component).init(std.testing.allocator);
defer ranges.deinit();
try ranges.append(.{ .stage = 0, .range = .{ .start = 79, .end = 93 } });
try ranges.append(.{ .stage = 0, .range = .{ .start = 55, .end = 66 } });
try ranges.append(.{ .stage = 0, .range = .{ .start = 70, .end = 10 } });
mergeRanges(&ranges);
try std.testing.expectEqual(.{ .start = 70, .end = 93 }, ranges.items[0].range);
try std.testing.expectEqual(.{ .start = 55, .end = 66 }, ranges.items[1].range);
}
fn solve(alloc: mem.Allocator, input: []const u8) !usize {
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_values = UsizeSet.init(alloc);
var working_values = UsizeSet.init(alloc);
defer last_values.deinit();
defer working_values.deinit();
var ranges = std.ArrayList(Component).init(alloc);
defer ranges.deinit();
var lowest_location: usize = std.math.maxInt(usize);
var low_loc: usize = std.math.maxInt(usize);
var seeds_index: usize = 0;
while (seeds_index < seeds.len) : (seeds_index += 2) {
last_values.clearRetainingCapacity();
working_values.clearRetainingCapacity();
std.debug.print("= seeding {d}/{d} =\n", .{ seeds_index, seeds.len });
const start = seeds[seeds_index];
const range = seeds[seeds_index + 1];
for (start..start + range) |seed| {
// std.debug.print("seed {d}\n", .{seed});
try working_values.put(seed, {});
}
// Reset parse input.
it = util.splitLines(input);
_ = it.next().?;
var current_component: []const u8 = undefined;
while (it.next()) |line| {
if (line.len == 0) {
std.debug.print("== swap ==\n", .{});
// Copy all remaining
var lv_it = last_values.iterator();
while (lv_it.next()) |entry| {
try working_values.put(entry.key_ptr.*, {});
}
// Swap working sets
mem.swap(UsizeSet, &last_values, &working_values);
working_values.clearRetainingCapacity();
} 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 {
std.debug.print("== {s} {d}/{d}\n", .{ current_component, working_values.count(), last_values.count() });
const map = try util.parseIntsScalar(usize, alloc, line, .{});
defer alloc.free(map);
var to_delete = UsizeSet.init(alloc);
defer to_delete.deinit();
var lv_it = last_values.iterator();
while (lv_it.next()) |entry| {
// if (transitioned[index]) {
// std.debug.print("{d} already mapped\n", .{index});
// continue :map_blk;
// }
const item = entry.key_ptr.*;
if (map[1] <= item and item <= map[1] + map[2]) {
const offset = @as(isize, @intCast(map[0])) - @as(isize, @intCast(map[1]));
const res: usize = @intCast(@as(isize, @intCast(item)) + offset);
// std.debug.print("{d} => {d}\n", .{ item, res });
try working_values.put(res, {});
try to_delete.put(item, {});
}
}
var td_it = to_delete.iterator();
while (td_it.next()) |entry| {
// std.debug.print("pop {d}\n", .{entry.key_ptr.*});
_ = last_values.remove(entry.key_ptr.*);
}
}
}
var lv_it = last_values.iterator();
while (lv_it.next()) |value| {
low_loc = @min(low_loc, value.key_ptr.*);
{
std.debug.print("= seeding {d} =\n", .{seeds.len});
var index: usize = 0;
while (index < seeds.len) : (index += 2) {
try ranges.append(.{
.stage = 0,
.range = .{
.start = seeds[index],
.end = seeds[index] + seeds[index + 1],
},
});
}
}
return .{ .a = low_loc, .b = 0 };
var current_stage: usize = 0;
while (it.next()) |line| {
if (line.len == 0) {
std.debug.print("== finalise ==\n", .{});
for (ranges.items, 0..) |item, index| {
if (item.stage != current_stage) {
ranges.items[index] = .{ .stage = current_stage, .range = item.range };
}
}
mergeRanges(&ranges);
} else if (mem.endsWith(u8, line, "map:")) {
current_stage += 1;
} else {
std.debug.print("== stage {d} map {s} ==\n", .{ current_stage, line });
const map_line = try util.parseIntsScalar(usize, alloc, line, .{});
defer alloc.free(map_line);
const map = Map{
.offset = @as(isize, @intCast(map_line[0])) - @as(isize, @intCast(map_line[1])),
.source = .{ .start = map_line[1], .end = map_line[1] + map_line[2] },
};
var i: usize = ranges.items.len;
while (i != 0) : (i -= 1) {
if (ranges.items[i - 1].stage == current_stage) continue;
const item = ranges.swapRemove(i - 1);
std.debug.print("item {d}/{d} {d}..{d}\n", .{ i, ranges.items.len + 1, item.range.start, item.range.end });
if (item.range.intersect(.{ .start = 0, .end = map.source.start })) |section| {
// Non-transitioning section.
std.debug.print("=> s {d}..{d}\n", .{ section.start, section.end });
try ranges.append(.{ .stage = item.stage, .range = section });
}
if (item.range.intersect(map.source)) |section| {
// Transitioning section.
const range = Range(usize){
.start = @intCast(@as(isize, @intCast(section.start)) + map.offset),
.end = @intCast(@as(isize, @intCast(section.end)) + map.offset),
};
std.debug.print("=> m {d}..{d}\n", .{ range.start, range.end });
try ranges.append(.{
.stage = current_stage,
.range = range,
});
}
if (item.range.intersect(.{ .start = map.source.end, .end = std.math.maxInt(usize) })) |section| {
// Non-transitioning section.
std.debug.print("=> e {d}..{d}\n", .{ section.start, section.end });
try ranges.append(.{ .stage = item.stage, .range = section });
}
}
}
}
for (ranges.items) |item| {
std.debug.print("{any}\n", .{item.range});
lowest_location = @min(lowest_location, item.range.start);
}
return lowest_location;
}
test "silver" {
@ -156,7 +218,7 @@ test "silver" {
;
_ = input;
// const sln = try solve(std.testing.allocator, input);
// try std.testing.expectEqual(@as(usize, 35), sln.a);
// try std.testing.expectEqual(@as(usize, 35), sln);
}
test "gold" {
@ -196,5 +258,5 @@ test "gold" {
\\56 93 4
;
const sln = try solve(std.testing.allocator, input);
try std.testing.expectEqual(@as(usize, 46), sln.a);
try std.testing.expectEqual(@as(usize, 46), sln);
}