結果
| 問題 | No.2411 Reverse Directions | 
| コンテスト | |
| ユーザー |  sotanishy | 
| 提出日時 | 2023-08-11 23:05:43 | 
| 言語 | PyPy3 (7.3.15) | 
| 結果 | 
                                AC
                                 
                             | 
| 実行時間 | 183 ms / 2,000 ms | 
| コード長 | 2,240 bytes | 
| コンパイル時間 | 255 ms | 
| コンパイル使用メモリ | 82,032 KB | 
| 実行使用メモリ | 122,180 KB | 
| 最終ジャッジ日時 | 2024-11-18 18:23:12 | 
| 合計ジャッジ時間 | 4,738 ms | 
| ジャッジサーバーID (参考情報) | judge4 / judge2 | 
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| ファイルパターン | 結果 | 
|---|---|
| sample | AC * 3 | 
| other | AC * 29 | 
ソースコード
import sys
input = sys.stdin.readline
move = [(1, 0), (0, 1), (-1, 0), (0, -1)]
dirs = "DRUL"
def bfs(si, sj):
    from collections import deque
    INF = 10**18
    dist = [[INF] * W for _ in range(H)]
    prv = [[-1] * W for _ in range(H)]
    dist[si][sj] = 0
    que = deque([(si, sj)])
    while que:
        i, j = que.popleft()
        for k, (di, dj) in enumerate(move):
            ni, nj = i+di, j+dj
            if 0 <= ni < H and 0 <= nj < W and dist[ni][nj] == INF and S[ni][nj] == '.':
                dist[ni][nj] = dist[i][j] + 1
                prv[ni][nj] = k
                que.append((ni, nj))
    return dist, prv
def out(si, sj, d):
    print("Yes")
    res = []
    i, j = si, sj
    while True:
        p = prvs[i][j]
        if p == -1:
            break
        res.append(p)
        di, dj = move[p ^ 2]
        i += di
        j += dj
    res = res[::-1]
    for k, (di, dj) in enumerate(move):
        ni, nj = si+di, sj+dj
        if 0 <= ni < H and 0 <= nj < W and S[ni][nj] == '.':
            for l in range(L-1-len(res)):
                res.append(k ^ ((l % 2)*2))
            break
    for k in range(R-L+1):
        res.append(d[k % 2])
    i, j = si, sj
    while True:
        p = prvt[i][j]
        if p == -1:
            break
        res.append(p ^ 2)
        di, dj = move[p ^ 2]
        i += di
        j += dj
    if S[H-2][W-1] == '.':
        for k in range(K-len(res)):
            res.append([2, 0][k % 2])
    else:
        for k in range(K-len(res)):
            res.append([3, 1][k % 2])
    print("".join(map(lambda k: dirs[k], res)))
H, W, K, L, R = map(int, input().split())
S = [input().rstrip() for _ in range(H)]
if (H+W) % 2 != K % 2 or (R - L + 1) % 2 != 0:
    print("No")
    exit()
dists, prvs = bfs(0, 0)
distt, prvt = bfs(H-1, W-1)
for i in range(H):
    for j in range(W):
        if (dists[i][j] - (L - 1)) % 2 == 0 and dists[i][j] <= L-1 and distt[i][j] <= K-R:
            # i
            if 0 < i < H-1 and S[i-1][j] == '.' and S[i+1][j] == '.':
                out(i, j, [0, 2])
                exit()
            # j
            if 0 < j < W-1 and S[i][j-1] == '.' and S[i][j+1] == '.':
                out(i, j, [1, 3])
                exit()
print("No")
            
            
            
        