69 lines
1.5 KiB
C++
69 lines
1.5 KiB
C++
//
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// Created by Matthew Gretton-Dann on 02/12/2021.
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//
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#include <iostream>
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#include <string>
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enum Direction { north, east, south, west };
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auto main() -> int
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{
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std::string line;
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if (!std::getline(std::cin, line)) {
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std::cerr << "Failed to read line.\n";
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return 1;
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}
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Direction direction{north};
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int horiz{0};
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int vert{0};
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for (std::size_t pos{0}; pos < line.size(); pos += 2) {
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switch (line.at(pos)) {
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case 'L':
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if (direction == Direction::north) {
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direction = Direction::west;
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}
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else {
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direction = static_cast<Direction>(static_cast<int>(direction) - 1);
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}
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break;
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case 'R':
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if (direction == Direction::west) {
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direction = Direction::north;
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}
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else {
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direction = static_cast<Direction>(static_cast<int>(direction) + 1);
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}
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break;
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default:
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abort();
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}
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++pos;
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assert(pos < line.size());
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std::size_t idx{0};
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auto dist{static_cast<int>(std::stoul(line.substr(pos), &idx))};
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pos += idx;
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switch (direction) {
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case Direction::north:
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vert += dist;
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break;
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case Direction::east:
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horiz += dist;
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break;
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case Direction::south:
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vert -= dist;
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break;
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case Direction::west:
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horiz -= dist;
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break;
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default:
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abort();
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}
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}
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horiz = std::abs(horiz);
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vert = std::abs(vert);
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std::cout << "We end up " << horiz << " + " << vert << " = " << horiz + vert << " blocks away.\n";
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return 0;
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} |