aocpp/2022/04.cpp

#include <cstddef>
#include <cstdio>
#include <iostream>
#include <sstream>
#include <stdexcept>
#include <string>
#include <tuple>

#include <doctest.h>

#include <aocpp/Startup.hpp>

namespace {

auto Solve(std::istream & in) -> std::pair<std::size_t, std::size_t>
{
  std::size_t p1{0}, p2{0};
  std::string line;
  while (std::getline(in, line)) {
    unsigned a,b,c,d;
    if (4 != std::sscanf(line.c_str(), "%u-%u,%u-%u\n", &a, &b, &c, &d)) {
      throw std::runtime_error{"bad input"};
    }
    
    if (a <= c && d <= b || c <= a && b <= d) p1++;
    
    if (a <= c && c <= b || a <= d && d <= b ||
        c <= a && a <= d || c <= b && b <= d) p2++;
  }
  return {p1, p2};
}


} // namespace

TEST_SUITE("2022-04 examples") {
  TEST_CASE("example") {
    std::istringstream in {
      "2-4,6-8\n"
      "2-3,4-5\n"
      "5-7,7-9\n"
      "2-8,3-7\n"
      "6-6,4-6\n"
      "2-6,4-8\n"};
    auto [p1,p2] = Solve(in);
    CHECK(p1 == 2);
    CHECK(p2 == 4);
  }
}

auto Main(std::istream & in, std::ostream & out) -> void
{
  auto const [p1,p2] = Solve(in);
  out << "Part 1: " << p1 << std::endl;
  out << "Part 2: " << p2 << std::endl;
}