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i don't know why i did that so stupidly this is like 25x faster

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Lucia Ceionia
2024-12-06 01:48:26 -06:00
parent 613edfd80b
commit dabcdfc2e1
1 changed files with 9 additions and 11 deletions
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20
06/src/main.zig
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@@ -101,38 +101,36 @@ fn run2(s: []const u8) !u64 {
var map2: [256][256]u8 = undefined;
@memcpy(&map2, &omap);
var prev_states = std.ArrayList(u32).init(alloc);
y = 0;
while (y < 256) : (y += 1) {
if (map[y][2] == 0) continue;
x = 0;
while (x < 256) : (x += 1) {
// attempt new obstacle... this is ugly and painfully slow
// attempt new obstacle... this is ugly
// but i'm lazy
if (y == sy and x == sx) continue;
if (map[y][x] == 'X') {
prev_states.clearRetainingCapacity();
map2[y][x] = '#';
var iy = sy;
var ix = sx;
dy = -1;
dx = 0;
var dir: u8 = 0;
var prev_states: [256][256][4]bool = .{.{.{false}**4}**256}**256;
while (map2[iy][ix] != 0) {
const state: u32 = @intCast((@as(usize,@bitCast(dy))<<24)|(@as(usize,@bitCast(dx))<<16)|(iy<<8)|(ix));
const idx = std.mem.indexOfScalar(u32, prev_states.items, state);
if (idx) |_| {
if (prev_states[iy][ix][dir]) {
total += 1;
break;
}
try prev_states.append(state);
prev_states[iy][ix][dir] = true;
ny = @intCast(@as(isize,@intCast(iy)) + dy);
nx = @intCast(@as(isize,@intCast(ix)) + dx);
while (map2[ny][nx] == '#') {
if (dy == -1 and dx == 0) { dy = 0; dx = 1; }
else if (dy == 0 and dx == 1) { dy = 1; dx = 0; }
else if (dy == 1 and dx == 0) { dy = 0; dx = -1; }
else { dy = -1; dx = 0; }
if (dir == 0) { dy = 0; dx = 1; dir = 1; }
else if (dir == 1) { dy = 1; dx = 0; dir = 2; }
else if (dir == 2) { dy = 0; dx = -1; dir = 3; }
else { dy = -1; dx = 0; dir = 0; }
ny = @intCast(@as(isize,@intCast(iy)) + dy);
nx = @intCast(@as(isize,@intCast(ix)) + dx);
}