60 lines
1.4 KiB
C++
60 lines
1.4 KiB
C++
//
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// Created by Matthew Gretton-Dann on 10/12/2021.
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//
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#include <cassert>
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#include <iostream>
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#include <map>
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#include <stack>
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#include <string>
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#include <vector>
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auto main() -> int
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{
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std::map<char, char> matches{{'(', ')'}, {'[', ']'}, {'{', '}'}, {'<', '>'}};
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std::map<char, unsigned> scores{{')', 1}, {']', 2}, {'}', 3}, {'>', 4}};
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std::string line;
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std::vector<std::uint64_t> line_scores;
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while (std::getline(std::cin, line)) {
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bool incomplete{true};
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std::stack<char> expecting;
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for (auto c : line) {
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if (auto it = matches.find(c); it != matches.end()) {
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expecting.push(it->second);
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}
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else if (!expecting.empty()) {
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if (c == expecting.top()) {
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expecting.pop();
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}
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else {
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incomplete = false;
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break;
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}
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}
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else {
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abort();
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}
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}
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if (!incomplete) {
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continue;
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}
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// expecting has the characters we expect.
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std::uint64_t score{0};
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while (!expecting.empty()) {
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score *= 5;
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auto score_it{scores.find(expecting.top())};
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assert(score_it != scores.end());
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score += score_it->second;
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expecting.pop();
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}
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line_scores.push_back(score);
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}
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std::sort(line_scores.begin(), line_scores.end());
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std::cout << "Middle score: " << line_scores.at(line_scores.size() / 2) << '\n';
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return 0;
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}
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