58 lines
1.1 KiB
C++
58 lines
1.1 KiB
C++
//
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// Created by Matthew Gretton-Dann on 06/12/2021.
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//
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#include <algorithm>
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#include <iostream>
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#include <string>
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auto generate_data(std::string const& s) -> std::string
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{
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std::string s2;
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std::string result{s};
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result.push_back('0');
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std::reverse_copy(s.begin(), s.end(), std::back_inserter(s2));
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std::transform(s2.begin(), s2.end(), std::back_inserter(result), [](char c) {
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if (c == '1') {
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return '0';
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}
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if (c == '0') {
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return '1';
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}
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abort();
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});
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return result;
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}
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auto checksum(std::string const& s) -> std::string
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{
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std::string result;
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for (std::size_t i{0}; i < s.size(); i += 2) {
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if (s[i] == s[i + 1]) {
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result.push_back('1');
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}
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else {
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result.push_back('0');
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}
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}
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return result;
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}
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auto main() -> int
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{
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constexpr unsigned len{35651584};
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std::string line;
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if (!std::getline(std::cin, line)) {
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std::cerr << "Unable to read line\n";
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return 1;
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}
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while (line.size() < len) {
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line = generate_data(line);
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}
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line.resize(len);
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while (line.size() % 2 == 0) {
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line = checksum(line);
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}
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std::cout << "Checksum " << line << '\n';
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return 0;
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} |