Add 2017 day 11 puzzles

2017/puzzle-11-01.cc

@@ -0,0 +1,60 @@
+#include <iostream>
+#include <string>
+
+using Coord = std::pair<int, int>;
+
+auto move(Coord const& c, std::string const& dir) -> Coord
+{
+  if (dir == "nw") {
+    return {c.first - 1, c.second + 1};
+  }
+  if (dir == "n") {
+    return {c.first, c.second + 2};
+  }
+  if (dir == "ne") {
+    return {c.first + 1, c.second + 1};
+  }
+  if (dir == "se") {
+    return {c.first + 1, c.second - 1};
+  }
+  if (dir == "s") {
+    return {c.first, c.second - 2};
+  }
+  if (dir == "sw") {
+    return {c.first - 1, c.second - 1};
+  }
+  abort();
+}
+
+auto main() -> int
+{
+  std::string line;
+  if (!std::getline(std::cin, line)) {
+    std::cerr << "Unable to read line\n";
+    return 1;
+  }
+
+  std::size_t idx{0};
+  Coord pos{0, 0};
+  while (idx < line.size()) {
+    auto next{line.find(',', idx)};
+    if (next == std::string::npos) {
+      next = line.size();
+    }
+    pos = move(pos, line.substr(idx, next - idx));
+
+    idx = next + 1;
+  }
+
+  std::cout << "Ended up at (" << pos.first << ", " << pos.second << ") moves away.\n";
+  /* We move horizontally pos.first steps - which gets us up to pos.first steps vertically as well.
+   * Then we move the remaining vertical distances.  */
+  auto x_dist{std::abs(pos.first)};
+  auto y_dist{std::abs(pos.second)};
+  auto moves{x_dist};
+  if (y_dist > x_dist) {
+    moves += (y_dist - x_dist) / 2;
+  }
+  std::cout << "Ended up " << moves << " moves away.\n";
+  return 0;
+}

2017/puzzle-11-02.cc

@@ -0,0 +1,69 @@
+#include <iostream>
+#include <string>
+
+using Coord = std::pair<int, int>;
+
+auto move(Coord const& c, std::string const& dir) -> Coord
+{
+  if (dir == "nw") {
+    return {c.first - 1, c.second + 1};
+  }
+  if (dir == "n") {
+    return {c.first, c.second + 2};
+  }
+  if (dir == "ne") {
+    return {c.first + 1, c.second + 1};
+  }
+  if (dir == "se") {
+    return {c.first + 1, c.second - 1};
+  }
+  if (dir == "s") {
+    return {c.first, c.second - 2};
+  }
+  if (dir == "sw") {
+    return {c.first - 1, c.second - 1};
+  }
+  abort();
+}
+
+auto dist(Coord const& pos) -> int
+{
+  /* We move horizontally pos.first steps - which gets us up to pos.first steps vertically as well.
+   * Then we move the remaining vertical distances.  */
+  auto x_dist{std::abs(pos.first)};
+  auto y_dist{std::abs(pos.second)};
+  auto moves{x_dist};
+  if (y_dist > x_dist) {
+    moves += (y_dist - x_dist) / 2;
+  }
+  return moves;
+}
+
+auto main() -> int
+{
+  std::string line;
+  if (!std::getline(std::cin, line)) {
+    std::cerr << "Unable to read line\n";
+    return 1;
+  }
+
+  std::size_t idx{0};
+  Coord pos{0, 0};
+  int max_dist{0};
+  while (idx < line.size()) {
+    auto next{line.find(',', idx)};
+    if (next == std::string::npos) {
+      next = line.size();
+    }
+    pos = move(pos, line.substr(idx, next - idx));
+    if (max_dist < dist(pos)) {
+      max_dist = dist(pos);
+    }
+    idx = next + 1;
+  }
+
+  std::cout << "Ended up at (" << pos.first << ", " << pos.second << ") moves away.\n";
+  std::cout << "Ended up " << dist(pos) << " moves away.\n";
+  std::cout << "Max distance away " << max_dist << '\n';
+  return 0;
+}