Thraix
101 lines
2.2 KiB
C++
101 lines
2.2 KiB
C++
#include "common/aoc.h"
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namespace y2021::day13
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{
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void Fold(std::set<Index2D>& indices, bool x, int fold)
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{
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std::set<Index2D> newIndices;
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for (auto& index : indices)
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{
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// y axis
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if (x)
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{
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Index2D newIndex = index;
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if (newIndex.x > fold)
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newIndex.x = fold - (newIndex.x - 1) % fold - 1;
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newIndices.emplace(newIndex);
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}
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else
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{
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Index2D newIndex = index;
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if (newIndex.y > fold)
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newIndex.y = fold - (newIndex.y - 1) % fold - 1;
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newIndices.emplace(newIndex);
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}
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}
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indices = newIndices;
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}
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struct Paper
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{
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std::set<Index2D> indices;
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std::vector<std::pair<bool, int>> folds;
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};
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REGISTER_DAY(2021, Day13, Paper, int);
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REGISTER_TEST_EXAMPLE(2021, Day13, ExampleInput, 1, 17);
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REGISTER_TEST(2021, Day13, Input, 1, 716);
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REGISTER_TEST_EXAMPLE(2021, Day13, ExampleInput, 2, 16);
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REGISTER_TEST(2021, Day13, Input, 2, 97);
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READ_INPUT(input)
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{
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Paper paper;
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std::string str;
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while (getline(input, str))
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{
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if (str.empty())
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break;
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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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paper.indices.emplace(index);
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}
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while (getline(input, str))
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{
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char c, c2;
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std::string s;
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int i;
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std::stringstream ss{str};
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ss >> s >> s >> c >> c2 >> i;
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paper.folds.emplace_back(c == 'x', i);
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}
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return paper;
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}
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OUTPUT1(input)
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{
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std::set<Index2D> indices = input.indices;
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Fold(indices, input.folds.front().first, input.folds.front().second);
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return indices.size();
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}
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OUTPUT2(input)
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{
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std::set<Index2D> indices = input.indices;
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for (auto& fold : input.folds)
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{
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Fold(indices, fold.first, fold.second);
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}
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Index2D max = *indices.begin();
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for (auto index : indices)
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{
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max.x = std::max(index.x, max.x);
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max.y = std::max(index.y, max.y);
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}
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Array2D<char> board{max.x + 1, max.y + 1};
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board.Fill(' ');
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for (auto& index : indices)
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{
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board[index] = '#';
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}
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std::cout << board;
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// Not the "correct" output to part 2, but it verifies something at least
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return indices.size();
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}
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}
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