--- /dev/null
+use core
+
+PART :: 1
+
+#if PART == 1 {
+
+Die :: struct {
+ value: u32;
+ rolls: u32;
+}
+
+#inject Die {
+ make :: () -> Die {
+ return .{ 1, 0 };
+ }
+
+ roll :: (d: ^Die) -> u32 {
+ defer d.value += 1;
+ defer d.rolls += 1;
+ return d.value;
+ }
+}
+
+Player :: struct {
+ square: u32;
+ score: u32;
+}
+
+#inject Player {
+ move :: (p: ^Player, squares: u32) {
+ p.square += squares;
+ p.square %= 10;
+
+ p.score += (p.square + 1);
+ }
+}
+
+main :: () {
+ p1, p2: Player;
+
+ for os.with_file("./tests/aoc-2021/input/day21.txt") {
+ r := io.reader_make(it);
+
+ l1 := r->read_line(consume_newline=true);
+ l2 := r->read_line(consume_newline=true);
+
+ _, s1 := string.bisect(l1, #char ":");
+ _, s2 := string.bisect(l2, #char ":");
+
+ string.strip_whitespace(^s1);
+ string.strip_whitespace(^s2);
+
+ p1.square = ~~ (conv.str_to_i64(s1) - 1);
+ p2.square = ~~ (conv.str_to_i64(s2) - 1);
+ }
+
+ die := Die.make();
+ losing_score: u32;
+
+ while true {
+ play :: macro (player, opponent: ^Player) {
+ r1 := die->roll();
+ r2 := die->roll();
+ r3 := die->roll();
+
+ player->move(r1 + r2 + r3);
+
+ if player.score >= 1000 {
+ losing_score = opponent.score;
+ break;
+ }
+ }
+
+ play(^p1, ^p2);
+ play(^p2, ^p1);
+ }
+
+ println(losing_score * die.rolls);
+}
+
+} // End of part 1
+
+
+#if PART == 2 {
+
+Player :: struct {
+ square: u32;
+ score: u64;
+}
+
+#inject Player {
+ hash :: (p: Player) -> u32 {
+ h := 7;
+ h += h << 5 + hash.to_u32(p.square);
+ h += h << 5 + hash.to_u32(p.score);
+ return h;
+ }
+
+ move :: (p: Player, m: u32) -> Player {
+ n := p;
+ n.square += m;
+ n.square %= 10;
+
+ n.score += ~~(n.square + 1);
+ return n;
+ }
+}
+
+#operator == (p1, p2: Player) => p1.square == p2.square && p1.score == p2.score;
+
+
+Case :: struct {
+ multiplier: u32;
+ spaces: u32;
+}
+
+cases := Case.[
+ Case.{ 1, 3 },
+ Case.{ 3, 4 },
+ Case.{ 6, 5 },
+ Case.{ 7, 6 },
+ Case.{ 6, 7 },
+ Case.{ 3, 8 },
+ Case.{ 1, 9 },
+]
+
+calc_wins_memo :: (p1, p2: Player, player_1_turn: bool) -> (u64, u64) {
+ #persist memo: Map(Pair(Pair(Player, Player), bool), Pair(u64, u64));
+
+ if memo->has(.{.{p1, p2}, player_1_turn}) {
+ v := memo->get(.{.{p1, p2}, player_1_turn});
+ return v.first, v.second;
+ }
+
+ v1, v2 := calc_wins(p1, p2, player_1_turn);
+ memo[.{.{p1, p2}, player_1_turn}] = .{v1, v2};
+ return v1, v2;
+}
+
+calc_wins :: (p1, p2: Player, player_1_turn := true) -> (u64, u64) {
+ if p1.score >= 21 {
+ return 1, 0;
+ }
+
+ elseif p2.score >= 21 {
+ return 0, 1;
+ }
+
+ else {
+ w1, w2: u64;
+
+ if player_1_turn {
+ for^ cases {
+ n1, n2 := calc_wins_memo(
+ p1->move(it.spaces),
+ p2,
+ false
+ );
+
+ w1 += n1 * ~~it.multiplier;
+ w2 += n2 * ~~it.multiplier;
+ }
+
+ } else {
+ for^ cases {
+ n1, n2 := calc_wins_memo(
+ p1,
+ p2->move(it.spaces),
+ true
+ );
+
+ w1 += n1 * ~~it.multiplier;
+ w2 += n2 * ~~it.multiplier;
+ }
+ }
+
+ return w1, w2;
+ }
+}
+
+main :: () {
+ p1, p2: Player;
+
+ for os.with_file("./tests/aoc-2021/input/day21.txt") {
+ r := io.reader_make(it);
+
+ l1 := r->read_line(consume_newline=true);
+ l2 := r->read_line(consume_newline=true);
+
+ _, s1 := string.bisect(l1, #char ":");
+ _, s2 := string.bisect(l2, #char ":");
+
+ string.strip_whitespace(^s1);
+ string.strip_whitespace(^s2);
+
+ p1.square = cast(i32) (conv.str_to_i64(s1) - 1);
+ p2.square = cast(i32) (conv.str_to_i64(s2) - 1);
+ }
+
+ w1, w2 := calc_wins(p1, p2);
+ println(w1);
+ println(w2);
+ println(math.max(w1, w2));
+
+}
+
+}
+
+
+
+Pair :: struct (T1: type_expr, T2: type_expr) {
+ first: T1;
+ second: T2;
+}
+
+#inject Pair {
+ hash :: (p: Pair($T/hash.Hashable, $R/hash.Hashable)) -> u32 {
+ h := 7;
+ h += h << 5 + hash.to_u32(p.first);
+ h += h << 5 + hash.to_u32(p.second);
+ return h;
+ }
+}
+
+#operator == (p1: Pair, p2: typeof p1) =>
+ p1.first == p2.first && p1.second == p2.second;
+
projects / onyx.git / commitdiff