86 lines
1.9 KiB
C++
86 lines
1.9 KiB
C++
#include "common/aoc.h"
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namespace y2016::day17
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{
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REGISTER_DAY(2016, Day17, std::string, std::string);
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REGISTER_TEST_EXAMPLE(2016, Day17, ExampleInput, 1, "DRURDRUDDLLDLUURRDULRLDUUDDDRR");
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REGISTER_TEST(2016, Day17, Input, 1, "DUDDRLRRRD");
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REGISTER_TEST_EXAMPLE(2016, Day17, ExampleInput, 2, "830");
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REGISTER_TEST(2016, Day17, Input, 2, "578");
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READ_INPUT(input)
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{
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std::vector<int> vec;
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std::string str;
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getline(input, str);
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return str;
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}
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struct State
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{
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std::string str{""};
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int x{0};
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int y{0};
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};
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bool IsOpen(char c)
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{
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return c >= 'b' && c <= 'f';
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}
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void Branch(const State& state, std::queue<State>& queue)
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{
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std::string hash = Md5::Hash(state.str);
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if (state.y > 0 && IsOpen(hash[0]))
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queue.emplace(State{state.str + "U", state.x, state.y - 1});
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if (state.y < 3 && IsOpen(hash[1]))
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queue.emplace(State{state.str + "D", state.x, state.y + 1});
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if (state.x > 0 && IsOpen(hash[2]))
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queue.emplace(State{state.str + "L", state.x - 1, state.y});
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if (state.x < 3 && IsOpen(hash[3]))
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queue.emplace(State{state.str + "R", state.x + 1, state.y});
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}
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bool IsGoal(const State& state)
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{
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return state.x == 3 && state.y == 3;
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}
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OUTPUT1(input)
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{
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std::queue<State> queue;
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queue.emplace(State{input, 0, 0});
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while (!queue.empty())
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{
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State state = queue.front();
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queue.pop();
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if (IsGoal(state))
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return state.str.substr(input.size());
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Branch(state, queue);
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}
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return "";
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}
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OUTPUT2(input)
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{
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std::queue<State> queue;
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queue.emplace(State{input, 0, 0});
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int longest = 0;
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while (!queue.empty())
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{
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State state = queue.front();
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queue.pop();
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if (IsGoal(state))
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{
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longest = state.str.size() - input.size();
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continue;
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}
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Branch(state, queue);
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}
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return std::to_string(longest);
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}
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}
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