Thraix
97 lines
2.1 KiB
C++
97 lines
2.1 KiB
C++
#include "common/aoc.h"
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namespace y2024::day18
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{
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using Memory = std::map<Index2D, int>;
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REGISTER_DAY(2024, Day18, Memory, int32_t);
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REGISTER_TEST_EXAMPLE(2024, Day18, ExampleInput, 1, 22);
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REGISTER_TEST(2024, Day18, Input, 1, 304);
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REGISTER_TEST_EXAMPLE(2024, Day18, ExampleInput, 2, 20);
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REGISTER_TEST(2024, Day18, Input, 2, 2876);
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READ_INPUT(input)
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{
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std::map<Index2D, int> memory;
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std::string str;
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int i = 0;
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while (std::getline(input, str))
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{
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Index2D index;
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std::stringstream ss{str};
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ss >> index.x >> "," >> index.y;
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memory.emplace(index, i);
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i++;
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}
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return memory;
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}
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struct Map
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{
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const std::map<Index2D, int>& memory;
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int size;
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int time;
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};
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std::vector<std::pair<int, Index2D>> Branch(const Map& map, const Index2D& current)
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{
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std::vector<std::pair<int, Index2D>> branch;
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for (auto& dir : Helper::GetNeighborDirections())
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{
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Index2D pos = current + dir;
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if (pos.x < 0 || pos.y < 0 || pos.x > map.size || pos.y > map.size)
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continue;
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auto it = map.memory.find(pos);
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if (it == map.memory.end() || it->second >= map.time)
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branch.emplace_back(1, pos);
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}
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return branch;
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}
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bool Goal(const Map& map, const Index2D& current)
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{
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return current.x == map.size && current.y == map.size;
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}
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bool ValidPath(const Map& map, int index)
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{
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Map cpy = map;
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cpy.time = index;
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return Helper::Dijkstras(cpy, Index2D{0, 0}, Branch, Goal) != 0;
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}
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OUTPUT1(input)
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{
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int32_t sum = 0;
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int time = 1024;
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int size = 70;
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if (isExample)
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{
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size = 6;
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time = 12;
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}
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Map map{input, size, time};
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return Helper::Dijkstras(map, Index2D{0, 0}, Branch, Goal);
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}
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OUTPUT2(input)
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{
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int size = 70;
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if (isExample)
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size = 6;
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Map map{input, size, 0};
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int result = Helper::BinarySearch(map, 0, input.size(), ValidPath);
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for (auto& index : input)
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{
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if (index.second == result)
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{
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std::cout << index.first.x << "," << index.first.y << std::endl;
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return result;
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}
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}
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return 0;
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}
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}
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