結果
問題 | No.3096 Snake Path |
ユーザー |
|
提出日時 | 2025-04-06 16:55:33 |
言語 | PyPy3 (7.3.15) |
結果 |
AC
|
実行時間 | 971 ms / 2,000 ms |
コード長 | 3,383 bytes |
コンパイル時間 | 498 ms |
コンパイル使用メモリ | 82,456 KB |
実行使用メモリ | 135,184 KB |
最終ジャッジ日時 | 2025-04-06 16:55:47 |
合計ジャッジ時間 | 13,016 ms |
ジャッジサーバーID (参考情報) |
judge2 / judge5 |
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ファイルパターン | 結果 |
---|---|
other | AC * 35 |
ソースコード
# input import sys input = sys.stdin.readline II = lambda : int(input()) MI = lambda : map(int, input().split()) LI = lambda : [int(a) for a in input().split()] SI = lambda : input().rstrip() LLI = lambda n : [[int(a) for a in input().split()] for _ in range(n)] LSI = lambda n : [input().rstrip() for _ in range(n)] MI_1 = lambda : map(lambda x:int(x)-1, input().split()) LI_1 = lambda : [int(a)-1 for a in input().split()] def graph(n:int, m:int, dir:bool=False, index:int=-1) -> list[set[int]]: edge = [set() for i in range(n+1+index)] for _ in range(m): a,b = map(int, input().split()) a += index b += index edge[a].add(b) if not dir: edge[b].add(a) return edge def graph_w(n:int, m:int, dir:bool=False, index:int=-1) -> list[set[tuple]]: edge = [set() for i in range(n+1+index)] for _ in range(m): a,b,c = map(int, input().split()) a += index b += index edge[a].add((b,c)) if not dir: edge[b].add((a,c)) return edge mod = 998244353 inf = 1001001001001001001 ordalp = lambda s : ord(s)-65 if s.isupper() else ord(s)-97 ordallalp = lambda s : ord(s)-39 if s.isupper() else ord(s)-97 yes = lambda : print("Yes") no = lambda : print("No") yn = lambda flag : print("Yes" if flag else "No") def acc(a:list[int]): sa = [0]*(len(a)+1) for i in range(len(a)): sa[i+1] = a[i] + sa[i] return sa prinf = lambda ans : print(ans if ans < 1000001001001001001 else -1) alplow = "abcdefghijklmnopqrstuvwxyz" alpup = "ABCDEFGHIJKLMNOPQRSTUVWXYZ" alpall = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ" URDL = {'U':(-1,0), 'R':(0,1), 'D':(1,0), 'L':(0,-1)} DIR_4 = [[-1,0],[0,1],[1,0],[0,-1]] DIR_8 = [[-1,0],[-1,1],[0,1],[1,1],[1,0],[1,-1],[0,-1],[-1,-1]] DIR_BISHOP = [[-1,1],[1,1],[1,-1],[-1,-1]] prime60 = [2,3,5,7,11,13,17,19,23,29,31,37,41,43,47,53,59] sys.set_int_max_str_digits(0) sys.setrecursionlimit(10**6) # import pypyjit # pypyjit.set_param('max_unroll_recursion=-1') from collections import defaultdict,deque from heapq import heappop,heappush from bisect import bisect_left,bisect_right DD = defaultdict BSL = bisect_left BSR = bisect_right n,k = MI() # 使った回数、位置(1,2,3) # この位置に下からくる通り数 dp = [[0,0,0] for i in range(k+2)] dp[0][0] = 1 cnt0 = DD(int) cnt2 = DD(int) for i in range(n): ndp = [[0,0,0] for i in range(k+2)] if i & 1 == 0: # 3-3パスがある時 for t in range(k+1): # そこからの遷移 ndp[t][0] += cnt2[t - 2 * i - 1] ndp[t][2] += cnt0[t - 2 * i] for t in range(k+1): s = sum(dp[t]) % mod ndp[t+1][0] += s ndp[t+1][1] += s ndp[t][2] += s cnt0[t - 2*i] += dp[t][0] cnt2[t - 2*i] += dp[t][2] else: for t in range(k+1): # そこからの遷移 ndp[t][0] += cnt2[t - 2 * i] ndp[t][2] += cnt0[t - 2 * i - 1] for t in range(k+1): s = sum(dp[t]) % mod ndp[t][0] += s ndp[t+1][1] += s ndp[t+1][2] += s cnt0[t - 2*i] += dp[t][0] cnt2[t - 2*i] += dp[t][2] dp = ndp if n & 1 == 0: ans = 0 for t in range(k+1): ans += dp[t][0] else: ans = 0 for t in range(k+1): ans += dp[t][2] print(ans % mod)