Initial commit

2015/puzzle-14-01.cc

@@ -0,0 +1,51 @@
+#include <cassert>
+#include <cctype>
+#include <climits>
+#include <functional>
+#include <iostream>
+#include <map>
+#include <regex>
+#include <set>
+#include <string>
+#include <variant>
+
+using Distance = unsigned long;
+
+Distance distance(std::string const &s, unsigned t) {
+  static const std::regex re("(\\w+) can fly (\\d+) km/s for (\\d+) seconds?, "
+                             "but then must rest for (\\d+) seconds?.");
+  std::smatch m;
+  if (std::regex_search(s, m, re)) {
+    unsigned fly_speed = std::stoul(m.str(2));
+    unsigned fly_time = std::stoul(m.str(3));
+    unsigned rest_time = std::stoul(m.str(4));
+
+    // Period and number of them
+    unsigned period = fly_time + rest_time;
+    unsigned periods = t / period;
+
+    // How far did we fly in the complete periods.
+    Distance result = (fly_speed * fly_time * periods);
+
+    // And the remainder distance
+    t -= periods * period;
+    t = std::min(t, fly_time);
+    result += t * fly_speed;
+
+    std::cout << m.str(1) << "(" << fly_speed << ", " << fly_time << ", "
+              << rest_time << ") = " << result << "\n";
+    return result;
+  } else {
+    assert(false);
+  }
+}
+
+int main(int argc, char **argv) {
+  Distance max_d = 0;
+  for (std::string line; std::getline(std::cin, line);) {
+    max_d = std::max(max_d, distance(line, 2503));
+  }
+
+  std::cout << "Max distance: " << max_d << "\n";
+  return 0;
+}