結果

問題 No.228 ゆきこちゃんの 15 パズル
コンテスト
ユーザー lam6er
提出日時 2025-03-31 17:46:35
言語 PyPy3
(7.3.15)
結果
WA  
実行時間 -
コード長 2,562 bytes
コンパイル時間 445 ms
コンパイル使用メモリ 82,220 KB
実行使用メモリ 54,228 KB
最終ジャッジ日時 2025-03-31 17:47:13
合計ジャッジ時間 1,760 ms
ジャッジサーバーID
（参考情報） 		judge3 / judge5
このコードへのチャレンジ
（要ログイン）
ファイルパターン 結果
sample AC * 3
other AC * 16 WA * 1
権限があれば一括ダウンロードができます

ソースコード

diff # 

def main():
    # Read input
    grid = []
    for _ in range(4):
        grid.append(list(map(int, input().split())))
    
    # Determine target positions and find the blank (0) position
    target_positions = {}
    blank_pos = None
    for i in range(4):
        for j in range(4):
            num = grid[i][j]
            if num == 0:
                blank_pos = (i + 1, j + 1)  # Convert to 1-based index
            else:
                target_positions[num] = (i + 1, j + 1)  # Store as 1-based
    
    # Condition 1: Solvability check (parity of inversion count and blank row difference)
    # Compute inversion count of target (excluding 0)
    flattened = []
    for row in grid:
        for num in row:
            if num != 0:
                flattened.append(num)
    inversion = 0
    for i in range(len(flattened)):
        for j in range(i + 1, len(flattened)):
            if flattened[i] > flattened[j]:
                inversion += 1
    
    initial_blank_row = 4
    target_blank_row = blank_pos[0]
    row_diff = abs(initial_blank_row - target_blank_row)
    condition1 = (inversion % 2) == (row_diff % 2)
    
    if not condition1:
        print("No")
        return
    
    # Condition 2: All manhattan distances between initial and target positions are 0 or 1
    condition2 = True
    for num in range(1, 16):  # Numbers 1 to 15
        # Initial position of num is based on standard initial 15-puzzle
        initial_i = (num - 1) // 4 + 1
        initial_j = (num - 1) % 4 + 1
        target_pos = target_positions.get(num)
        if target_pos is None:
            # This shouldn't happen as per the problem statement
            print("No")
            return
        dx = abs(initial_i - target_pos[0])
        dy = abs(initial_j - target_pos[1])
        if dx + dy > 1:
            condition2 = False
            break
    
    if not condition2:
        print("No")
        return
    
    # Condition3: D and K must have the same parity
    # Compute D (Manhattan distance of blank's movement)
    initial_blank = (4, 4)
    D = abs(initial_blank[0] - blank_pos[0]) + abs(initial_blank[1] - blank_pos[1])
    
    # Compute K (number of moved tiles)
    K = 0
    for num in range(1, 16):
        initial_i = (num - 1) // 4 + 1
        initial_j = (num - 1) % 4 + 1
        target_i, target_j = target_positions[num]
        if initial_i != target_i or initial_j != target_j:
            K += 1
    
    if (D % 2) != (K % 2):
        print("No")
        return
    
    print("Yes")

if __name__ == "__main__":
    main()
0