Initial commit

2020/puzzle-22-01.cc

@@ -0,0 +1,76 @@
+#include <algorithm>
+#include <array>
+#include <cassert>
+#include <iostream>
+#include <list>
+#include <map>
+#include <regex>
+#include <set>
+#include <string>
+#include <tuple>
+#include <vector>
+
+using Card = unsigned;
+using Cards = std::list<Card>;
+using Score = unsigned long;
+
+struct Player {
+  Player(std::istream &is) {
+    std::string line;
+    if (!std::getline(is, name_)) {
+      assert(false);
+    }
+    while (std::getline(is, line)) {
+      if (line == "") {
+        break;
+      }
+      cards_.push_back(std::stoul(line));
+    }
+  }
+
+  bool empty() const { return cards_.empty(); }
+  Card front() const { return cards_.front(); }
+  void pop_front() { cards_.pop_front(); }
+  void push_back(Card c) { cards_.push_back(c); }
+
+  Score score() const {
+    Score r = 0;
+    unsigned idx = 1;
+    for (auto it = cards_.rbegin(); it != cards_.rend(); ++it) {
+      r += idx * *it;
+      ++idx;
+    }
+    return r;
+  }
+
+private:
+  std::string name_;
+  Cards cards_;
+};
+
+Score play_game(Player &p1, Player &p2) {
+  while (!p1.empty() && !p2.empty()) {
+    Card c1 = p1.front();
+    Card c2 = p2.front();
+    p1.pop_front();
+    p2.pop_front();
+    if (c1 > c2) {
+      p1.push_back(c1);
+      p1.push_back(c2);
+    } else if (c1 < c2) {
+      p2.push_back(c2);
+      p2.push_back(c1);
+    }
+  }
+
+  return p1.score() + p2.score();
+}
+
+int main(void) {
+  Player player1(std::cin);
+  Player player2(std::cin);
+
+  Score final_score = play_game(player1, player2);
+  std::cout << "Final score: " << final_score << "\n";
+  return 0;
+}