結果

問題 No.2411 Reverse Directions
ユーザー polylogK
提出日時 2023-08-11 23:23:01
言語 C++17
(gcc 13.3.0 + boost 1.87.0)
結果
AC  
実行時間 45 ms / 2,000 ms
コード長 3,569 bytes
コンパイル時間 2,333 ms
コンパイル使用メモリ 208,596 KB
最終ジャッジ日時 2025-02-16 02:08:55
ジャッジサーバーID
（参考情報） 		judge4 / judge4
このコードへのチャレンジ
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ファイルパターン 結果
sample AC * 3
other AC * 29
権限があれば一括ダウンロードができます
コンパイルメッセージ
main.cpp: In function ‘int main()’:
main.cpp:26:10: warning: ignoring return value of ‘int scanf(const char*, ...)’ declared with attribute ‘warn_unused_result’ [-Wunused-result]
   26 |     scanf("%d%d%d%d%d", &h, &w, &k, &l, &r);
      |     ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

ソースコード

diff #
プレゼンテーションモードにする

#include <bits/stdc++.h>
using namespace std::literals::string_literals;
using i64 = std::int_fast64_t;
using std::cerr;
using std::cin;
using std::cout;
using std::endl;
#if defined(DONLINE_JUDGE)
#define NDEBUG
#elif defined(ONLINE_JUDGE)
#define NDEBUG
#endif
template <typename T>
std::vector<T> make_v(size_t a) {
    return std::vector<T>(a);
}
template <typename T, typename... Ts>
auto make_v(size_t a, Ts... ts) {
    return std::vector<decltype(make_v<T>(ts...))>(a, make_v<T>(ts...));
}
int main() {
    int h, w, k, l, r;
    scanf("%d%d%d%d%d", &h, &w, &k, &l, &r);
    std::vector<std::string> s(h);
    for (auto& v : s) std::cin >> v;
    --l;
    if ((r - l) % 2) {
        puts("No");
        return 0;
    }
    if (l == 0 or r == k) {
        puts("No");
        return 0;
    }
    std::vector<int> dy{0, 1, 0, -1};
    std::vector<int> dx{1, 0, -1, 0};
    std::string tos = "RDLU";
    auto g = [](char c) {
        if (c == 'R') return 0;
        if (c == 'D') return 1;
        if (c == 'L') return 2;
        if (c == 'U') return 3;
        return -1;
    };
    auto f = [&](int sy, int sx) {
        std::vector d(h, std::vector<int>(w, 1 << 30));
        d[sy][sx] = 0;
        std::queue<std::pair<int, int>> qu({{sy, sx}});
        while (!qu.empty()) {
            auto [y, x] = qu.front();
            qu.pop();
            for (int k = 0; k < 4; ++k) {
                const int ny = y + dy[k];
                const int nx = x + dx[k];
                if (nx < 0 or ny < 0 or nx >= w or ny >= h) continue;
                if (s[ny][nx] == '#') continue;
                if (d[ny][nx] != 1 << 30) continue;
                qu.push({ny, nx});
                d[ny][nx] = d[y][x] + 1;
            }
        }
        return d;
    };
    auto sakina = [&](int y, int x, int ty, int tx) {
        auto ds = f(y, x);
        auto dt = f(ty, tx);
        std::string ans = "";
        while (y != ty or x != tx) {
            for (int k = 0; k < 4; ++k) {
                const int ny = y + dy[k];
                const int nx = x + dx[k];
                if (ny < 0 or nx < 0 or ny >= h or nx >= w) continue;
                if (s[ny][nx] == '#') continue;
                if (ds[y][x] + 1 + dt[ny][nx] != ds[ty][tx]) continue;
                ans += tos[k];
                y = ny;
                x = nx;
                break;
            }
        }
        return ans;
    };
    auto d0 = f(0, 0);
    auto dn = f(h - 1, w - 1);
    if (k % 2 != dn[0][0] % 2) {
        puts("No");
        return 0;
    }
    for (int i = 0; i < h; ++i) {
        for (int j = 0; j < w; ++j) {
            if (s[i][j] == '#') continue;
            if (d0[i][j] > l) continue;
            if (d0[i][j] % 2 != l % 2) continue;
            if (dn[i][j] > k - r) continue;
            int dir = -1;
            if (i + 1 < h and i - 1 >= 0 and s[i + 1][j] == '.' and
                s[i - 1][j] == '.') {
                dir = 1;
            }
            if (j + 1 < w and j - 1 >= 0 and s[i][j + 1] == '.' and
                s[i][j - 1] == '.') {
                dir = 0;
            }
            if (dir == -1) continue;
            std::string front = sakina(0, 0, i, j);
            std::string back = sakina(i, j, h - 1, w - 1);
            while (front.size() + back.size() < k) {
                front += tos[dir];
                front += tos[(dir + 2) % 4];
            }
            puts("Yes");
            std::cout << front + back << std::endl;
            return 0;
        }
    }
    puts("No");
    return 0;
}
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