2017-05

2017/05.cpp

@@ -0,0 +1,64 @@
+#include <cstdint>
+#include <iostream>
+#include <sstream>
+#include <string>
+#include <tuple>
+#include <vector>
+
+#include <doctest.h>
+
+#include <aocpp/Startup.hpp>
+
+namespace {
+
+auto Parse(std::istream & in) -> std::vector<std::int64_t> {
+  std::vector<std::int64_t> result;
+  std::int64_t x;
+  while (in >> x) {
+    result.push_back(x);
+  }
+  return result;
+}
+
+auto Run1(std::vector<std::int64_t> program) -> std::size_t {
+  std::int64_t cursor = 0;
+  std::size_t n = 0;
+
+  while (0 <= cursor && cursor < program.size()) {
+    cursor += program[cursor]++;
+    n++;
+  }
+
+  return n;
+}
+
+auto Run2(std::vector<std::int64_t> program) -> std::size_t {
+  std::int64_t cursor = 0;
+  std::size_t n = 0;
+
+  while (0 <= cursor && cursor < program.size()) {
+    auto & p = program[cursor];
+    cursor += p;
+    p += p >= 3 ? -1 : 1;
+    n++;
+  }
+
+  return n;
+}
+
+} // namespace
+
+TEST_SUITE("2017-05 examples") {
+  TEST_CASE("example") {
+    std::istringstream in { "0\n3\n0\n1\n-3\n" };
+    auto input = Parse(in);
+    CHECK(Run1(input) == 5);
+    CHECK(Run2(input) == 10);
+  }
+}
+
+auto main(int argc, char** argv) -> int {
+  auto input = Parse(*aocpp::Startup(argc, argv));
+  std::cout << "Part 1: " << Run1(input) << std::endl;
+  std::cout << "Part 2: " << Run2(std::move(input)) << std::endl;
+}

2017/06.cpp

@@ -22,7 +22,7 @@ auto Parse(std::istream & in) -> Banks<16> {
       throw std::runtime_error{"bad input"};
     }
   }
-  
+
   return result;
 }
 
@@ -58,7 +58,7 @@ auto CycleSearch(Banks<N> & banks)
 TEST_SUITE("2017-06 examples") {
   TEST_CASE("example") {
     Banks<4> banks {0, 2, 7, 0};
-    
+
     SUBCASE("single step") {
       Redistribute(banks);
       REQUIRE(banks == Banks<4>{2, 4, 1, 2});
@@ -85,4 +85,4 @@ auto main(int argc, char** argv) -> int {
   auto answer = CycleSearch(input);
   std::cout << "Part 1: " << answer.first << std::endl;
   std::cout << "Part 2: " << answer.second << std::endl;
-}
+}

2017/CMakeLists.txt

@@ -1,3 +1,6 @@
+add_executable(2017_05 05.cpp)
+target_link_libraries(2017_05 aocpp)
+
 add_executable(2017_06 06.cpp)
 target_link_libraries(2017_06 aocpp)