結果

問題 No.2131 Concon Substrings (COuNt Version)
ユーザー lam6er
提出日時 2025-03-20 20:52:14
言語 PyPy3
(7.3.15)
結果
AC  
実行時間 634 ms / 2,000 ms
コード長 1,763 bytes
コンパイル時間 177 ms
コンパイル使用メモリ 81,992 KB
実行使用メモリ 83,556 KB
最終ジャッジ日時 2025-03-20 20:52:31
合計ジャッジ時間 5,163 ms
ジャッジサーバーID
（参考情報） 		judge2 / 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 * 4
other AC * 16
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 # 

import sys
from collections import defaultdict

MOD = 998244353

def main():
    N = int(sys.stdin.readline())

    prev_dp = [defaultdict(int) for _ in range(3)]
    prev_dp[0][0] = 1  # Initial state: 0 chars processed, state 0, k=0

    for _ in range(N):
        next_dp = [defaultdict(int) for _ in range(3)]
        for s in range(3):
            for k in prev_dp[s]:
                count = prev_dp[s][k]
                if count == 0:
                    continue
                if s == 0:
                    # Transition for choosing 'c'
                    next_s = 1
                    next_k = k
                    next_dp[next_s][next_k] = (next_dp[next_s][next_k] + count) % MOD
                    # Transition for others (25 possibilities)
                    next_dp[0][k] = (next_dp[0][k] + count * 25) % MOD
                elif s == 1:
                    # Transition for choosing 'o'
                    next_s = 2
                    next_k = k
                    next_dp[next_s][next_k] = (next_dp[next_s][next_k] + count) % MOD
                    # Transition for others (25 possibilities)
                    next_dp[1][k] = (next_dp[1][k] + count * 25) % MOD
                elif s == 2:
                    # Transition for choosing 'n'
                    next_s = 0
                    next_k = k + 1
                    next_dp[next_s][next_k] = (next_dp[next_s][next_k] + count) % MOD
                    # Transition for others (25 possibilities)
                    next_dp[2][k] = (next_dp[2][k] + count * 25) % MOD
        prev_dp = next_dp

    result = 0
    for s in range(3):
        for k in prev_dp[s]:
            result = (result + k * prev_dp[s][k]) % MOD
    print(result)

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