wash day07

src/day07.zig

@@ -4,18 +4,14 @@ const mem = std.mem;
 
 pub fn main() !void {
     const input = @embedFile("data/day07.txt");
-    const sln = try solve2(util.gpa, input);
-    std.debug.print("{d}\n", .{sln.a});
-    std.debug.print("{d}\n", .{sln.b});
+    const part1 = try solve(util.gpa, input, jack);
+    const part2 = try solve(util.gpa, input, joker);
+    std.debug.print("{d}\n", .{part1});
+    std.debug.print("{d}\n", .{part2});
 }
 
 const Cards = [5]u8;
 
-const Solution = struct {
-    a: usize,
-    b: usize,
-};
-
 const Score = enum(u8) {
     fiveKind,
     fourKind,
@@ -32,13 +28,16 @@ const Hand = struct {
     score: Score,
 };
 
-fn fixCards(cards: *[5]u8) void {
+const jack = 10;
+const joker = 0;
+
+fn fixCards(cards: *[5]u8, jValue: u8) void {
     for (cards, 0..) |card, i| {
         cards[i] = switch (card) {
             'A' => 13,
             'K' => 12,
             'Q' => 11,
-            'J' => 0,
+            'J' => jValue,
             'T' => 9,
             '2'...'9' => card - '1',
             else => unreachable,
@@ -52,24 +51,6 @@ fn u8gt(context: void, a: u8, b: u8) bool {
 }
 
 fn scoreHand(cards: Cards) Score {
-    var dups: [14]u8 = undefined;
-    @memset(&dups, 0);
-    for (cards) |a| {
-        dups[a] += 1;
-    }
-    std.mem.sort(u8, &dups, {}, u8gt);
-    return switch (dups[0]) {
-        5 => .fiveKind,
-        4 => .fourKind,
-        3 => if (dups[1] == 2) .fullHouse else .threeKind,
-        2 => if (dups[1] == 2) .twoPair else .onePair,
-        else => .high,
-    };
-}
-
-const joker = 0;
-
-fn scoreHand2(cards: Cards) Score {
     var jokers: usize = 0;
     var dups: [14]u8 = undefined;
     @memset(&dups, 0);
@@ -80,7 +61,7 @@ fn scoreHand2(cards: Cards) Score {
             dups[a] += 1;
         }
     }
-    std.mem.sort(u8, &dups, {}, u8gt);
+    mem.sort(u8, &dups, {}, u8gt);
     return switch (dups[0] + jokers) {
         5 => .fiveKind,
         4 => .fourKind,
@@ -102,64 +83,28 @@ fn compareHand(context: void, a: Hand, b: Hand) bool {
     unreachable;
 }
 
-fn sortHands(hands: *std.ArrayList(Hand)) !void {
-    std.mem.sort(Hand, hands.items, {}, compareHand);
-}
-
-fn solve(alloc: mem.Allocator, input: []const u8) !Solution {
+fn solve(alloc: mem.Allocator, input: []const u8, jValue: u8) !u32 {
     var hands = try std.ArrayList(Hand).initCapacity(alloc, 1001);
     defer hands.deinit();
 
     var it = util.splitLines(input);
     while (it.next()) |line| {
         if (line.len == 0) continue;
-
         var cards = line[0..5].*;
-        fixCards(&cards);
+        fixCards(&cards, jValue);
         const bid = try std.fmt.parseInt(u32, line[6..], 10);
         const score = scoreHand(cards);
-        const hand = Hand{ .cards = cards, .bid = bid, .score = score };
-        try hands.append(hand);
+        try hands.append(.{ .cards = cards, .bid = bid, .score = score });
     }
 
-    // std.debug.print("{any}\n", .{hands.items});
-    try sortHands(&hands);
+    mem.sort(Hand, hands.items, {}, compareHand);
 
-    var partA: usize = 0;
+    var winnings: u32 = 0;
     for (hands.items, 1..) |hand, rank| {
-        // std.debug.print("{d} * {d}\n", .{ hand.bid, rank });
-        partA += hand.bid * rank;
+        winnings += hand.bid * @as(u32, @intCast(rank));
     }
 
-    return .{ .a = partA, .b = 0 };
-}
-
-fn solve2(alloc: mem.Allocator, input: []const u8) !Solution {
-    var hands = try std.ArrayList(Hand).initCapacity(alloc, 1001);
-    defer hands.deinit();
-
-    var it = util.splitLines(input);
-    while (it.next()) |line| {
-        if (line.len == 0) continue;
-
-        var cards = line[0..5].*;
-        fixCards(&cards);
-        const bid = try std.fmt.parseInt(u32, line[6..], 10);
-        const score = scoreHand2(cards);
-        const hand = Hand{ .cards = cards, .bid = bid, .score = score };
-        try hands.append(hand);
-    }
-
-    // std.debug.print("{any}\n", .{hands.items});
-    try sortHands(&hands);
-
-    var partB: usize = 0;
-    for (hands.items, 1..) |hand, rank| {
-        // std.debug.print("{d} * {d}\n", .{ hand.bid, rank });
-        partB += hand.bid * rank;
-    }
-
-    return .{ .a = 0, .b = partB };
+    return winnings;
 }
 
 test "silver" {
@@ -170,8 +115,8 @@ test "silver" {
         \\KTJJT 220
         \\QQQJA 483
     ;
-    const sln = try solve(std.testing.allocator, input);
-    try std.testing.expectEqual(@as(usize, 6440), sln.a);
+    const sln = try solve(std.testing.allocator, input, jack);
+    try std.testing.expectEqual(@as(usize, 6440), sln);
 }
 
 test "gold" {
@@ -182,6 +127,6 @@ test "gold" {
         \\KTJJT 220
         \\QQQJA 483
     ;
-    const sln = try solve2(std.testing.allocator, input);
-    try std.testing.expectEqual(@as(usize, 5905), sln.b);
+    const sln = try solve(std.testing.allocator, input, joker);
+    try std.testing.expectEqual(@as(usize, 5905), sln);
 }