結果

問題 No.3291 K-step Navigation
ユーザー lif4635
提出日時 2025-10-03 23:20:00
言語 PyPy3
(7.3.15)
結果
AC  
実行時間 687 ms / 3,000 ms
コード長 2,200 bytes
コンパイル時間 3,021 ms
コンパイル使用メモリ 82,560 KB
実行使用メモリ 122,128 KB
最終ジャッジ日時 2025-10-03 23:31:50
合計ジャッジ時間 10,009 ms
ジャッジサーバーID
（参考情報） 		judge5 / judge1
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ファイルパターン 結果
sample AC * 2
other AC * 51
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 # 

# 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()]

mod = 998244353
inf = 10 ** 18 + 10
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")

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, m, k, s, t = MI()
s -= 1
t -= 1


assert s != t

e = [[0] * n for i in range(n)]
e2 = [[] for i in range(n)]
for i in range(m):
    u, v = MI_1()
    e[u][v] = 1
    e[v][u] = 1
    e2[u].append(v)
    e2[v].append(u)
if k & 1:
    yes()
    exit()

p = sum(e[s]) - e[s][t]
q = sum(e[t]) - e[t][s]
if p or q:
    yes()
    exit()

if e[s][t] == 0:
    no()
    exit()

def solve(s):
    d = [[inf, inf] for i in range(n)]
    d[s][0] = 0
    st = deque([(s, 0)])
    while st:
        u, f = st.popleft()
        nd = d[u][f]
        for v in e2[u]:
            if d[v][f^1] == inf:
                d[v][f^1] = nd+1
                st.append((v, f^1))
    return d[s][1]

r = inf
for i in range(n):
    r = min(r, solve(i))

yn(r <= k-3)
0