From fa7a9aab14320494b0c4f577e3c007b3be9b770c Mon Sep 17 00:00:00 2001
From: xeals <dev@xeal.me>
Date: Wed, 13 Dec 2023 13:51:38 +1100
Subject: [PATCH] light washing, fix overflows

---
 src/day12.zig | 53 ++++++++++++---------------------------------------
 1 file changed, 12 insertions(+), 41 deletions(-)

diff --git a/src/day12.zig b/src/day12.zig
index 6981b16..ba43d41 100644
--- a/src/day12.zig
+++ b/src/day12.zig
@@ -22,8 +22,7 @@ fn hash(alloc: mem.Allocator, pattern: []const u8, groups: []const u8, curr_grou
     return try a.toOwnedSlice();
 }
 
-// Mystery records to whether they fit.
-var memo: std.StringHashMap(u32) = undefined;
+var memo: std.StringHashMap(usize) = undefined;
 
 fn clone(comptime T: type, alloc: mem.Allocator, s: []const T) ![]T {
     var a = try alloc.alloc(T, s.len);
@@ -31,32 +30,26 @@ fn clone(comptime T: type, alloc: mem.Allocator, s: []const T) ![]T {
     return a;
 }
 
-fn solvePattern(alloc: mem.Allocator, pattern: []const u8, groups: []const u8, curr_group: u8) !u32 {
-    std.debug.print("{s}, {any}, {}\n", .{ pattern, groups, curr_group });
-
+fn solvePattern(alloc: mem.Allocator, pattern: []const u8, groups: []const u8, curr_group: u8) !usize {
     const h = try hash(alloc, pattern, groups, curr_group);
     if (memo.get(h)) |m| {
         alloc.free(h);
-        std.debug.print("== short-circuit {}\n", .{m});
         return m;
     }
 
     if (pattern.len == 0) {
-        std.debug.print("== done {}\n", .{groups.len == 0});
         return if (groups.len == 0) 1 else 0;
     }
 
-    const res: u32 = b: {
+    const res: usize = b: {
         switch (pattern[0]) {
             '#' => {
                 // Too many #
                 if (groups.len == 0 or curr_group >= groups[0]) {
-                    std.debug.print("== bad fit\n", .{});
                     break :b 0;
                 }
                 // Special-case last #
                 if (pattern.len == 1 and groups.len == 1 and groups[0] == curr_group + 1) {
-                    std.debug.print("== done true\n", .{});
                     break :b 1;
                 }
                 break :b try solvePattern(alloc, pattern[1..], groups, curr_group + 1);
@@ -65,7 +58,6 @@ fn solvePattern(alloc: mem.Allocator, pattern: []const u8, groups: []const u8, c
                 if (curr_group > 0) {
                     if (groups.len == 0 or curr_group != groups[0]) {
                         // Too many #
-                        std.debug.print("== bad fit\n", .{});
                         break :b 0;
                     } else {
                         // Group done
@@ -85,7 +77,6 @@ fn solvePattern(alloc: mem.Allocator, pattern: []const u8, groups: []const u8, c
                 p1[0] = '#';
                 p2[0] = '.';
 
-                std.debug.print("=> test ?\n", .{});
                 break :b try solvePattern(alloc, p1, groups, curr_group) +
                     try solvePattern(alloc, p2, groups, curr_group);
             },
@@ -93,7 +84,6 @@ fn solvePattern(alloc: mem.Allocator, pattern: []const u8, groups: []const u8, c
         }
     };
 
-    std.debug.print("<= {s}, {any}, {} = {}\n", .{ pattern, groups, curr_group, res });
     try memo.put(h, res);
 
     return res;
@@ -109,16 +99,17 @@ fn unfold(alloc: mem.Allocator, input: []const u8, sep: u8) ![]const u8 {
 }
 
 fn solve(alloc: mem.Allocator, input: []const u8) !Solution {
-    memo = std.StringHashMap(u32).init(alloc);
+    memo = std.StringHashMap(usize).init(alloc);
     defer memo.deinit();
 
-    var sum1: u32 = 0;
-    var sum2: u32 = 0;
+    var sum1: usize = 0;
+    var sum2: usize = 0;
 
     var it = util.splitLines(input);
-    var i: u32 = 0;
+    var i: usize = 1;
     while (it.next()) |line| {
         if (line.len == 0) continue;
+        std.debug.print("line {} ", .{i});
 
         var lit = util.splitSpace(line);
         const pattern = lit.next().?;
@@ -131,7 +122,6 @@ fn solve(alloc: mem.Allocator, input: []const u8) !Solution {
         defer alloc.free(unfolded_pattern);
         defer alloc.free(unfolded_groups);
 
-        std.debug.print("---- {} ----\n", .{i});
         sum1 += try solvePattern(alloc, pattern, groups, 0);
         sum2 += try solvePattern(alloc, unfolded_pattern, unfolded_groups, 0);
         std.debug.print("{} {}\n", .{ sum1, sum2 });
@@ -159,34 +149,15 @@ test "silver" {
     try std.testing.expectEqual(@as(usize, 21), sln.a);
 }
 
-test "gold-2" {
+test "gold" {
     const input =
+        \\???.### 1,1,3
         \\.??..??...?##. 1,1,3
-    ;
-    const sln = try solve(std.testing.allocator, input);
-    try std.testing.expectEqual(@as(usize, 16384), sln.b);
-}
-
-test "gold-4" {
-    const input =
+        \\?#?#?#?#?#?#?#? 1,3,1,6
         \\????.#...#... 4,1,1
-    ;
-    const sln = try solve(std.testing.allocator, input);
-    try std.testing.expectEqual(@as(usize, 16), sln.b);
-}
-
-test "gold-5" {
-    const input =
         \\????.######..#####. 1,6,5
-    ;
-    const sln = try solve(std.testing.allocator, input);
-    try std.testing.expectEqual(@as(usize, 2500), sln.b);
-}
-
-test "gold-6" {
-    const input =
         \\?###???????? 3,2,1
     ;
     const sln = try solve(std.testing.allocator, input);
-    try std.testing.expectEqual(@as(usize, 506250), sln.b);
+    try std.testing.expectEqual(@as(usize, 525152), sln.b);
 }