better solution for day 19

1 files changed, 12 insertions, 24 deletions

diff --git a/2023/src/day19.cpp b/2023/src/day19.cpp
index a1d4eab..192e066 100644
--- a/2023/src/day19.cpp
+++ b/2023/src/day19.cpp
@@ -101,35 +101,23 @@ part2(map<string, tuple<vector<tuple<string, string, long, string>>, string>> ru
 
                 long result = 0;
 
-                bool run_trough = true;
                 for ( const auto& [key, cmp, value, target]: sub_rules ) {
-                        const auto [lo, hi] = ranges[key];
-                        pair<long, long> T; // NOLINT
-                        pair<long, long> F; // NOLINT
+                        auto sub_ranges = ranges;
+                        auto [lo, hi]   = ranges[key];
+
                         if ( cmp == "<" ) {
-                                T = { lo, min(value - 1, hi) };
-                                F = { max(value, lo), hi };
-                        }
-                        else {
-                                T = { max(value + 1, lo), hi };
-                                F = { lo, min(value, hi) };
-                        }
-                        if ( T.first <= T.second ) {
-                                auto copy = ranges;
-                                copy[key] = T;
-                                result += count(copy, target);
-                        }
-                        if ( F.first <= F.second ) {
-                                ranges[key] = F;
+                                sub_ranges[key] = { lo, value - 1 };
+                                ranges[key]     = { value, hi };
                         }
-                        else {
-                                run_trough = false;
-                                break;
+                        else /* if ( cmp == ">" ) */ {
+                                ranges[key]     = { lo, value };
+                                sub_ranges[key] = { value + 1, hi };
                         }
+
+                        result += count(sub_ranges, target);
                 }
-                if ( run_trough ) {
-                        result += count(ranges, fallback);
-                }
+
+                result += count(ranges, fallback);
 
                 return result;
         };