feat: add day 5

day5/CMakeLists.txt

@@ -0,0 +1,29 @@
+cmake_minimum_required(VERSION 3.10)
+
+# Project name and version
+project(Day5 VERSION 1.0)
+
+# Set default build type
+if(NOT CMAKE_BUILD_TYPE)
+    set(CMAKE_BUILD_TYPE Debug)
+endif()
+
+# 1. This is the critical line for Clangd. 
+# It generates the file clangd reads to know where headers are.
+set(CMAKE_EXPORT_COMPILE_COMMANDS ON)
+
+# Debug and Release flags
+set(CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_DEBUG} -g -O0 -Wall -Wextra")
+set(CMAKE_CXX_FLAGS_RELEASE "${CMAKE_CXX_FLAGS_RELEASE} -O3")
+
+# Specify C standard
+set(CMAKE_CXX_STANDARD 23)
+set(CMAKE_CXX_STANDARD_REQUIRED ON)
+
+# Add include directory
+include_directories(${PROJECT_SOURCE_DIR}/include)
+
+# Add executable
+add_executable(${PROJECT_NAME} 
+    src/main.cpp
+)

day5/Makefile

@@ -0,0 +1,13 @@
+
+
+clear:
+	rm -rf build/*
+
+run:
+	cp input.txt build
+	cp input_test.txt build
+	cd build && cmake .. && make && ./Day5 input_test.txt
+
+release:
+	cp input.txt build
+	cd build && cmake .. -DCMAKE_BUILD_TYPE=Release && make && ./Day5 input.txt

day5/flake.lock

@@ -0,0 +1,27 @@
+{
+  "nodes": {
+    "nixpkgs": {
+      "locked": {
+        "lastModified": 1756787288,
+        "narHash": "sha256-rw/PHa1cqiePdBxhF66V7R+WAP8WekQ0mCDG4CFqT8Y=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "d0fc30899600b9b3466ddb260fd83deb486c32f1",
+        "type": "github"
+      },
+      "original": {
+        "owner": "NixOS",
+        "ref": "nixos-unstable",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
+    "root": {
+      "inputs": {
+        "nixpkgs": "nixpkgs"
+      }
+    }
+  },
+  "root": "root",
+  "version": 7
+}

day5/flake.nix

@@ -0,0 +1,58 @@
+{
+  description = "A Nix-flake-based C/C++ development environment";
+
+  inputs.nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
+
+  outputs =
+    { self, nixpkgs }:
+    let
+      supportedSystems = [
+        "x86_64-linux"
+        "aarch64-linux"
+        "x86_64-darwin"
+        "aarch64-darwin"
+      ];
+      forEachSupportedSystem =
+        f:
+        nixpkgs.lib.genAttrs supportedSystems (
+          system:
+          f {
+            pkgs = import nixpkgs { inherit system; };
+          }
+        );
+    in
+    {
+      devShells = forEachSupportedSystem (
+        { pkgs }:
+        {
+          default =
+            pkgs.mkShell.override
+              {
+                # Override stdenv in order to change compiler:
+                # stdenv = pkgs.clangStdenv;
+              }
+
+              {
+                nativeBuildInputs = with pkgs; [
+                  pkg-config
+                ];
+                packages =
+                  with pkgs;
+                  [
+                    clang-tools
+                    cmake
+                    codespell
+                    cppcheck
+                    doxygen
+                    gtest
+                    lcov
+                    nodejs
+                    vscode-extensions.vadimcn.vscode-lldb
+                  ]
+                  ++ (if system == "aarch64-darwin" then [ ] else [ gdb ]);
+                CODELLDB_PATH = "${pkgs.vscode-extensions.vadimcn.vscode-lldb}/share/vscode/extensions/vadimcn.vscode-lldb/adapter/codelldb";
+              };
+        }
+      );
+    };
+}

day5/input_test.txt

@@ -0,0 +1,5 @@
+3-5
+10-14
+16-20
+12-18
+

day5/src/main.cpp

@@ -0,0 +1,123 @@
+#include <algorithm>
+#include <cmath>
+#include <cstdlib>
+#include <fstream>
+#include <iostream>
+#include <iterator>
+#include <numeric>
+#include <vector>
+
+typedef std::vector<std::tuple<long, long>> IngredientRanges;
+
+struct ParsedIngredients {
+  IngredientRanges ranges;
+  const std::vector<long> to_find;
+};
+
+bool is_ingredient_valid(IngredientRanges::const_iterator begin,
+                         IngredientRanges::const_iterator end, long find) {
+  auto distance = std::distance(begin, end);
+  if (distance == 0) {
+    return false;
+  }
+  if (distance == 1) {
+    return (find >= std::get<0>(*begin) && find <= std::get<1>(*begin));
+  }
+  auto middle = std::next(begin, distance / 2);
+  if (find < std::get<0>(*middle)) {
+    return is_ingredient_valid(begin, middle, find);
+  } else if (find > std::get<1>(*middle)) {
+    return is_ingredient_valid(middle, end, find);
+  }
+  return true;
+}
+
+void remove_included_ranges(IngredientRanges &ranges) {
+  // There are ranges such as:
+  // 1 - 9, followed by 2 - 7
+  // we remove 2-7 like ranges, since they're included in the previous one
+  long max_right = -1;
+  for (auto it = ranges.begin(); it != ranges.end();) {
+    long right_value = std::get<1>(*it);
+    if (right_value < max_right)
+      it = ranges.erase(it);
+    else
+      ++it;
+    max_right = right_value;
+  }
+}
+
+ParsedIngredients parse_input_file(const std::string &path) {
+  std::ifstream file;
+  std::string line;
+  IngredientRanges ingredient_ranges;
+  std::vector<long> to_find;
+
+  file.open(path);
+  if (file.is_open()) {
+    while (std::getline(file, line)) {
+      if (line.empty())
+        continue;
+      size_t pos = line.find('-');
+      if (pos != std::string::npos) {
+        long start = std::stol(line.substr(0, pos));
+        long end = std::stol(line.substr(pos + 1));
+        ingredient_ranges.emplace_back(start, end);
+      } else {
+        long parsed = std::stol(line);
+        to_find.emplace_back(parsed);
+      }
+    }
+  } else {
+    std::cerr << "Error opening file: " << path << std::endl;
+  }
+
+  std::sort(ingredient_ranges.begin(), ingredient_ranges.end());
+  return {ingredient_ranges, to_find};
+}
+
+long do_part1(const ParsedIngredients &parsed) {
+  long sum = 0;
+  for (const long f : parsed.to_find) {
+    sum += is_ingredient_valid(parsed.ranges.begin(), parsed.ranges.end(), f)
+               ? 1
+               : 0;
+  }
+  return sum;
+}
+
+long do_part2(const ParsedIngredients &parsed) {
+  long valid_ingredients = 0;
+  long max_right = -1;
+  for (const auto &range : parsed.ranges) {
+    long left = std::get<0>(range);
+    long right = std::get<1>(range);
+    if (left < max_right) {
+      valid_ingredients += right - max_right;
+    } else if (left == max_right) {
+      valid_ingredients += right - left;
+    } else {
+      valid_ingredients += right - left + 1;
+    }
+    max_right = right;
+  }
+  return valid_ingredients;
+}
+
+int main(int argc, char *argv[]) {
+  if (argc < 2) {
+    std::cout << "One argument required: input txt" << std::endl;
+  }
+
+  auto parsed_ingredients = parse_input_file(argv[1]);
+
+  remove_included_ranges(parsed_ingredients.ranges);
+
+  long s = do_part1(parsed_ingredients);
+  std::cout << "Part 1: " << s << std::endl;
+
+  s = do_part2(parsed_ingredients);
+  std::cout << "Part 2: " << s << std::endl;
+
+  return 0;
+}