제출 #742556

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
742556		bogdanvladmihai	Awesome Arrowland Adventure (eJOI19_adventure)	C++14	100 / 100	432 ms	12336 KiB

adventure

#include <iostream>
#include <vector>
#include <queue>
#include <utility>
#include <limits.h>
#include <tuple>

const std::vector<std::pair<int, int>> dirs = {{0, -1}, {-1, 0}, {0, 1}, {1, 0}};

inline bool inside(int x, int y, int N, int M) {
    return x >= 0 && y >= 0 && x < N && y < M;
}

int main() {
    std::ios_base::sync_with_stdio(false);
    std::cin.tie(nullptr);
    std::cout.tie(nullptr);

    int N, M;
    std::cin >> N >> M;
    std::vector<std::string> mat(N);
    for (auto &line : mat) {
        std::cin >> line;
    }
    std::vector<std::queue<std::pair<int, int>>> Q(4);
    std::vector<std::vector<int>> dist(N, std::vector<int>(M, INT_MAX / 2));
    if (mat[0][0] != 'X') {
        dist[0][0] = 0;
        Q[0].emplace(0, 0);
    }

    auto getTop = [&]() {
        for (int i = 0; i < 4; i++) {
            if (!Q[i].empty()) {
                auto answer = Q[i].front();
                Q[i].pop();
                return answer;
            }
        }
        return std::make_pair(-1, -1);
    };

    while (true) {
        int x, y;
        std::tie(x, y) = getTop();
        if (x == -1) {
            break;
        }
        int j = 0;
        switch (mat[x][y]) {
            case 'N':
                j = 1;
                break;
            case 'E':
                j = 2;
                break;
            case 'S':
                j = 3;
                break;
        }
        for (int i = 0; i < 4; i++) {
            int nx = x + dirs[(i + j) % 4].first, ny = y + dirs[(i + j) % 4].second;
            if (inside(nx, ny, N, M) && dist[nx][ny] > dist[x][y] + i) {
                dist[nx][ny] = dist[x][y] + i;
                if (mat[nx][ny] != 'X') {
                    Q[i].emplace(nx, ny);
                }
            }
        }
    }
    std::cout << (dist[N - 1][M - 1] < INT_MAX / 2 ? dist[N - 1][M - 1] : -1) << "\n";
    return 0;
}

• Subtask 1: 10 / 10
• Subtask 2: 12 / 12
• Subtask 3: 12 / 12
• Subtask 4: 16 / 16
• Subtask 5: 50 / 50