Add solution for 2022 day 17 Part 1

2022/puzzle-17-01.cc

@@ -0,0 +1,119 @@
+//
+// Created by Matthew Gretton-Dann on 17/12/2022.
+//
+
+#include <array>
+#include <iostream>
+#include <list>
+#include <map>
+#include <numeric>
+#include <regex>
+#include <set>
+#include <stdexcept>
+#include <utility>
+#include <vector>
+
+using Int = std::int64_t;
+using UInt = std::uint64_t;
+
+using namespace std::string_literals;
+using Shape = std::vector<std::string>;
+
+auto shapes_intersect(Shape const& tower, Shape const& shape, UInt x, UInt y) -> bool
+{
+  for (auto const& row : shape) {
+    UInt cx{x};
+    for (auto const& c : row) {
+      if (c != ' ' && tower[y][cx] != '.') {
+        return true;
+      }
+      ++cx;
+    }
+    ++y;
+  }
+  return false;
+}
+
+auto main() -> int
+{
+  std::string instructions;
+  if (!std::getline(std::cin, instructions)) {
+    std::cerr << "No input\n";
+    return EXIT_FAILURE;
+  }
+
+  UInt height{0};
+  std::string const floor{"+-------+"};
+  std::string const wall{"|.......|"};
+  Shape const horiz = {{"oooo"}};
+  Shape const plus = {{" o "}, {"ooo"}, {" o "}};
+  Shape const corner = {{"ooo"}, {"  o"}, {"  o"}};
+  Shape const vert = {{"o"}, {"o"}, {"o"}, {"o"}};
+  Shape const square = {{"oo"}, {"oo"}};
+  std::vector<Shape> const shapes{horiz, plus, corner, vert, square};
+
+  Shape tower{floor};
+  auto wind_it{instructions.begin()};
+  auto shape_it{shapes.begin()};
+  for (UInt i{0}; i < 2022; ++i) {
+    std::cout << " Shape " << i + 1 << " height: " << height << "\n";
+
+    // Where should the block appear?  (2, 3 + height).
+    UInt x{3};
+    UInt y{4 + height};
+
+    // Now make sure we have enough wall in the tower.
+    while (tower.size() < y + shape_it->size() + 1) {
+      tower.push_back(wall);
+    }
+
+    // Now do the instructions in turn:
+    while (true) {
+      // Wind movement
+      UInt const trial_x{x + (*wind_it == '>' ? 1 : -1)};
+      if (!shapes_intersect(tower, *shape_it, trial_x, y)) {
+        x = trial_x;
+      }
+
+      ++wind_it;
+      if (wind_it == instructions.end()) {
+        wind_it = instructions.begin();
+      }
+
+      // Downward movement
+      UInt const trial_y{y - 1};
+      if (!shapes_intersect(tower, *shape_it, x, trial_y)) {
+        y = trial_y;
+      }
+      else {
+        break;
+      }
+    }
+
+    // Insert the piece.
+    for (auto const& r : *shape_it) {
+      UInt cx{x};
+      for (auto c : r) {
+        if (c != ' ') {
+          tower[y][cx] = '#';
+        }
+        ++cx;
+      }
+      ++y;
+    }
+
+    // Now find the height.
+    height = tower.size() - 1;
+    while (tower[height].find("#") == std::string::npos) {
+      --height;
+    }
+
+    // Next shape
+    ++shape_it;
+    if (shape_it == shapes.end()) {
+      shape_it = shapes.begin();
+    }
+  }
+  std::cout << "Maximum height: " << height << "\n";
+  return EXIT_SUCCESS;
+}