2024 day 21: solve part 2

Author: yut23

2024/answer_tests/day21/example1.txt

@@ -1,2 +1,3 @@
 Day 21:
 126384
+154115708116294

2024/src/day21.cpp

@@ -16,26 +16,31 @@ int main(int argc, char **argv) {
     using namespace aoc::day21;
     auto codes = read_input(args.infile);
 
-    long total = 0;
+    long part_1 = 0;
+    long part_2 = 0;
     for (const auto &code : codes) {
         // one numeric keypad that a robot is using
-        std::vector<DirKey> keys = control_numeric(code.keys);
+        std::vector<Key> keys = code.keys;
         // two directional keypads that robots are using
-        for (int i = 0; i < 2; ++i) {
-            keys = control_directional(keys);
-        }
-        long complexity = keys.size() * code.numeric_value();
-        total += complexity;
+        long part_1_size = count_presses_memo(keys, 1 + 2);
+        // 25 directional keypads that robots are using
+        long part_2_size = count_presses_memo(keys, 1 + 25);
+        long complexity_1 = part_1_size * code.numeric_value();
+        part_1 += complexity_1;
+        long complexity_2 = part_2_size * code.numeric_value();
+        part_2 += complexity_2;
         if constexpr (aoc::DEBUG) {
             std::cerr << code.code << ": ";
             for (const auto key : keys) {
                 std::cerr << key;
             }
-            std::cerr << "\n  complexity = " << keys.size() << " * "
-                      << code.numeric_value() << " = " << complexity << "\n";
+            std::cerr << "\n  part 1 complexity = " << part_1_size << " * "
+                      << code.numeric_value() << " = " << complexity_1 << "\n";
+            std::cerr << "  part 2 complexity = " << part_2_size << " * "
+                      << code.numeric_value() << " = " << complexity_2 << "\n";
         }
     }
-    std::cout << total << "\n";
+    std::cout << part_1 << "\n" << part_2 << "\n";
 
     return 0;
 }