inga-lovinde
/
AdventOfCode-2023
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

day 17, part 1 (replaced depth-first with breadth-first, implemented ring queue, switched from up/down/left/right to vertical/horizontal), wrong answer

Browse Source
main
Inga 🏳‍🌈 11 months ago
parent 120b14f067
commit 11788cc1ed
1 changed files with 138 additions and 56 deletions
Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL
Show Stats Download Patch File Download Diff File
  1. 194
      day17-easy/src/main.zig

194
day17-easy/src/main.zig
Unescape View File

@ -44,67 +44,128 @@ fn StackList(comptime T: type, comptime capacity_type: type, comptime capacity:
};
}
const Direction = enum(u2) {
Up,
Down,
Left,
Right,
fn RingQueue(comptime T: type, comptime capacity_type: type, comptime capacity: capacity_type) type {
return struct {
const Self = @This();
mem: [capacity]T,
first: capacity_type,
next: capacity_type,
fn add(self: *Self, value: T) void {
std.debug.assert(self.next - self.first < capacity);
self.mem[self.next % capacity] = value;
self.next += 1;
}
fn take(self: *Self) T {
const result = self.mem[self.first % capacity];
self.first += 1;
return result;
}
fn isEmpty(self: *const Self) bool {
return self.next == self.first;
}
fn init() Self {
return Self{
.mem = undefined,
.first = 0,
.next = 0,
};
}
};
}
const Direction = enum(u8) {
Horizontal,
Vertical,
};
const ResultsByDirection = std.EnumArray(Direction, u32);
const Results = [150][150]ResultsByDirection;
const NextCellCoordinates = StackList([2]usize, usize, 3);
const Task = packed struct(u48) {
current_heat: u16,
x: u8,
y: u8,
entry_direction: Direction,
_: u8 = 0,
};
const NextTasks = StackList(Task, usize, 6);
fn getNextTasks(board: []const []const u8, task: Task) NextTasks {
var result = NextTasks.init();
const previous_direction: Direction = switch (task.entry_direction) {
.Vertical => .Horizontal,
.Horizontal => .Vertical,
};
fn fillResults(board: []const []const u8, results: *Results, x: usize, y: usize, entry_direction: Direction, depth: usize) void {
//std.debug.print("Solving for {d},{d}, {any}, depth: {d}, total: {d}\n", .{ x, y, entry_direction, depth, results.*[x][y].get(entry_direction) });
var previous_cells_list = StackList([2]usize, usize, 3).init();
switch (entry_direction) {
.Up => {
for (1..4) |delta| {
if (x + delta < board.len) {
previous_cells_list.add(.{ x + delta, y });
{
var previous_cells_list = StackList([2]u8, usize, 3).init();
switch (task.entry_direction) {
.Vertical => {
inline for (1..4) |delta| {
if (task.x + delta < board.len) {
previous_cells_list.add(.{ task.x + @as(u8, delta), task.y });
}
}
}
},
.Down => {
for (1..4) |delta| {
if (x >= delta) {
previous_cells_list.add(.{ x - delta, y });
},
.Horizontal => {
inline for (1..4) |delta| {
if (task.y + delta < board[task.x].len) {
previous_cells_list.add(.{ task.x, task.y + @as(u8, delta) });
}
}
}
},
.Left => {
for (1..4) |delta| {
if (y + delta < board[x].len) {
previous_cells_list.add(.{ x, y + delta });
},
}
var current_heat = task.current_heat;
for (previous_cells_list.getSlice()) |previous_cell| {
current_heat += board[previous_cell[0]][previous_cell[1]];
result.add(.{
.current_heat = current_heat,
.x = previous_cell[0],
.y = previous_cell[1],
.entry_direction = previous_direction,
});
}
}
{
var previous_cells_list = StackList([2]u8, usize, 3).init();
switch (task.entry_direction) {
.Vertical => {
inline for (1..4) |delta| {
if (task.x >= delta) {
previous_cells_list.add(.{ task.x - @as(u8, delta), task.y });
}
}
}
},
.Right => {
for (1..4) |delta| {
if (y >= delta) {
previous_cells_list.add(.{ x, y - delta });
},
.Horizontal => {
inline for (1..4) |delta| {
if (task.y >= delta) {
previous_cells_list.add(.{ task.x, task.y - @as(u8, delta) });
}
}
}
},
},
}
var current_heat = task.current_heat;
for (previous_cells_list.getSlice()) |previous_cell| {
current_heat += board[previous_cell[0]][previous_cell[1]];
result.add(.{
.current_heat = current_heat,
.x = previous_cell[0],
.y = previous_cell[1],
.entry_direction = previous_direction,
});
}
}
const previous_directions: [2]Direction = switch (entry_direction) {
.Up, .Down => .{ .Left, .Right },
.Left, .Right => .{ .Up, .Down },
};
//std.debug.print("Next tasks for {any}: {any}\n", .{ task, result.getSlice() });
var current_heat = results.*[x][y].get(entry_direction);
for (previous_cells_list.getSlice()) |previous_cell| {
current_heat += board[previous_cell[0]][previous_cell[1]];
for (previous_directions) |direction| {
if (results.*[previous_cell[0]][previous_cell[1]].get(direction) > current_heat) {
results.*[previous_cell[0]][previous_cell[1]].set(direction, current_heat);
fillResults(board, results, previous_cell[0], previous_cell[1], direction, depth + 1);
}
}
}
return result;
}
fn solveLines(lines: [][]u8) usize {
@ -116,26 +177,47 @@ fn solveLines(lines: [][]u8) usize {
}
}
const x_max = lines.len - 1;
const y_max = lines[x_max].len - 1;
const x_max = @as(u8, @intCast(lines.len - 1));
const y_max = @as(u8, @intCast(lines[x_max].len - 1));
var results: Results = [_][150]ResultsByDirection{[_]ResultsByDirection{ResultsByDirection.initFill(total_max)} ** 150} ** 150;
results[x_max][y_max].set(.Down, lines[x_max][y_max]);
results[x_max][y_max].set(.Right, lines[x_max][y_max]);
var tasks = RingQueue(Task, usize, 1_024_576).init();
tasks.add(.{
.current_heat = lines[x_max][y_max],
.x = x_max,
.y = y_max,
.entry_direction = .Horizontal,
});
tasks.add(.{
.current_heat = lines[x_max][y_max],
.x = x_max,
.y = y_max,
.entry_direction = .Vertical,
});
fillResults(lines, &results, x_max, y_max, .Down, 0);
fillResults(lines, &results, x_max, y_max, .Right, 0);
var i: usize = 0;
while (!tasks.isEmpty()) : (i += 1) {
//std.debug.print("Handling task {d}\n", .{i});
var current_task = tasks.take();
if (results[current_task.x][current_task.y].get(current_task.entry_direction) > current_task.current_heat) {
results[current_task.x][current_task.y].set(current_task.entry_direction, current_task.current_heat);
for (getNextTasks(lines, current_task).getSlice()) |next_task| {
tasks.add(next_task);
}
}
}
if (false) {
std.debug.print("Total tasks done: {d}\n", .{i});
for (0..lines.len) |x| {
for (0..lines[x].len) |y| {
std.debug.print("{d} ", .{@min(@min(results[x][y].get(.Up), results[x][y].get(.Down)), @min(results[x][y].get(.Left), results[x][y].get(.Right)))});
std.debug.print("{d}/{d} ", .{ results[x][y].get(.Horizontal), results[x][y].get(.Vertical) });
}
std.debug.print("\n", .{});
}
}
return results[0][0].get(.Down) - lines[0][0];
return results[0][0].get(.Vertical) - lines[0][0];
}
pub fn solveAll(reader: anytype) !usize {

Write Preview
Loading…
Cancel
Save