57 lines
1.1 KiB
C++
57 lines
1.1 KiB
C++
#include <fstream>
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#include <iostream>
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#include <string>
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#include <vector>
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#include <utility>
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std::vector<std::string> read_input_file() {
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std::ifstream file("input");
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std::vector<std::string> data;
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std::string line;
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while(std::getline(file, line))
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data.push_back(line);
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return data;
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}
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int count_trees(const std::vector<std::string> &map, const std::pair<int, int> &slope){
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int trees = 0;
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int x = slope.first;
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int y = slope.second;
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int w = map[0].size();
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int h = map.size();
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while(y < h) {
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if(map[y][x%w] == '#') trees++;
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x += slope.first;
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y += slope.second;
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}
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return trees;
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}
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int solve_a(const std::vector<std::string> &map) {
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return count_trees(map, {3, 1});
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}
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long solve_b(const std::vector<std::string> &map) {
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std::vector<std::pair<int, int>> slopes {{1, 1}, {3, 1}, {5, 1}, {7, 1}, {1, 2}};
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long result = 1;
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for(auto& slope: slopes) result *= count_trees(map, slope);
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return result;
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}
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int main() {
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auto data = read_input_file();
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std::cout << solve_a(data) << std::endl;
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std::cout << solve_b(data) << std::endl;
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return 0;
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}
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