結果
| 問題 | No.1833 Subway Planning |
| ユーザー |
 chineristAC
|
| 提出日時 | 2022-02-04 23:09:28 |
| 言語 | PyPy3 (7.3.15) |
| 結果 |
AC
|
| 実行時間 | 3,977 ms / 4,000 ms |
| コード長 | 20,965 bytes |
| コンパイル時間 | 252 ms |
| コンパイル使用メモリ | 82,304 KB |
| 実行使用メモリ | 315,964 KB |
| 最終ジャッジ日時 | 2024-06-11 12:44:00 |
| 合計ジャッジ時間 | 35,642 ms |
|
ジャッジサーバーID （参考情報） |
judge1 / judge5 |
（要ログイン）
テストケース
テストケース表示| 入力 | 結果 | 実行時間 実行使用メモリ |
|---|---|---|
| testcase_00 | AC | 59 ms
66,176 KB |
| testcase_01 | AC | 60 ms
66,432 KB |
| testcase_02 | AC | 62 ms
66,432 KB |
| testcase_03 | AC | 54 ms
66,432 KB |
| testcase_04 | AC | 1,004 ms
313,836 KB |
| testcase_05 | AC | 1,046 ms
313,664 KB |
| testcase_06 | AC | 2,374 ms
313,936 KB |
| testcase_07 | AC | 3,090 ms
315,964 KB |
| testcase_08 | AC | 3,977 ms
312,896 KB |
| testcase_09 | AC | 1,971 ms
313,380 KB |
| testcase_10 | AC | 1,252 ms
242,252 KB |
| testcase_11 | AC | 1,046 ms
229,640 KB |
| testcase_12 | AC | 983 ms
230,064 KB |
| testcase_13 | AC | 1,254 ms
228,708 KB |
| testcase_14 | AC | 799 ms
213,204 KB |
| testcase_15 | AC | 1,229 ms
207,140 KB |
| testcase_16 | AC | 1,595 ms
215,216 KB |
| testcase_17 | AC | 2,196 ms
200,492 KB |
| testcase_18 | AC | 2,167 ms
192,072 KB |
| testcase_19 | AC | 1,901 ms
191,812 KB |
| testcase_20 | AC | 1,453 ms
164,944 KB |
| testcase_21 | AC | 2,316 ms
313,412 KB |
| testcase_22 | AC | 1,995 ms
291,512 KB |
| testcase_23 | AC | 55 ms
66,560 KB |
| testcase_24 | AC | 55 ms
66,432 KB |
| testcase_25 | AC | 57 ms
66,432 KB |
ソースコード
def divisors(M):
d=[]
i=1
while M>=i**2:
if M%i==0:
d.append(i)
if i**2!=M:
d.append(M//i)
i=i+1
return d
def popcount(x):
x = x - ((x >> 1) & 0x55555555)
x = (x & 0x33333333) + ((x >> 2) & 0x33333333)
x = (x + (x >> 4)) & 0x0f0f0f0f
x = x + (x >> 8)
x = x + (x >> 16)
return x & 0x0000007f
def eratosthenes(n):
res=[0 for i in range(n+1)]
prime=set([])
for i in range(2,n+1):
if not res[i]:
prime.add(i)
for j in range(1,n//i+1):
res[i*j]=1
return prime
def factorization(n):
res=[]
for p in prime:
if n%p==0:
while n%p==0:
n//=p
res.append(p)
if n!=1:
res.append(n)
return res
def euler_phi(n):
res = n
for x in range(2,n+1):
if x ** 2 > n:
break
if n%x==0:
res = res//x * (x-1)
while n%x==0:
n //= x
if n!=1:
res = res//n * (n-1)
return res
def ind(b,n):
res=0
while n%b==0:
res+=1
n//=b
return res
def isPrimeMR(n):
if n==1:
return 0
d = n - 1
d = d // (d & -d)
L = [2, 3, 5, 7, 11, 13, 17]
for a in L:
t = d
y = pow(a, t, n)
if y == 1: continue
while y != n - 1:
y = (y * y) % n
if y == 1 or t == n - 1: return 0
t <<= 1
return 1
def findFactorRho(n):
from math import gcd
m = 1 << n.bit_length() // 8
for c in range(1, 99):
f = lambda x: (x * x + c) % n
y, r, q, g = 2, 1, 1, 1
while g == 1:
x = y
for i in range(r):
y = f(y)
k = 0
while k < r and g == 1:
ys = y
for i in range(min(m, r - k)):
y = f(y)
q = q * abs(x - y) % n
g = gcd(q, n)
k += m
r <<= 1
if g == n:
g = 1
while g == 1:
ys = f(ys)
g = gcd(abs(x - ys), n)
if g < n:
if isPrimeMR(g): return g
elif isPrimeMR(n // g): return n // g
return findFactorRho(g)
def primeFactor(n):
i = 2
ret = {}
rhoFlg = 0
while i*i <= n:
k = 0
while n % i == 0:
n //= i
k += 1
if k: ret[i] = k
i += 1 + i % 2
if i == 101 and n >= 2 ** 20:
while n > 1:
if isPrimeMR(n):
ret[n], n = 1, 1
else:
rhoFlg = 1
j = findFactorRho(n)
k = 0
while n % j == 0:
n //= j
k += 1
ret[j] = k
if n > 1: ret[n] = 1
if rhoFlg: ret = {x: ret[x] for x in sorted(ret)}
return ret
def divisors(n):
res = [1]
prime = primeFactor(n)
for p in prime:
newres = []
for d in res:
for j in range(prime[p]+1):
newres.append(d*p**j)
res = newres
res.sort()
return res
def xorfactorial(num):#排他的論理和の階乗
if num==0:
return 0
elif num==1:
return 1
elif num==2:
return 3
elif num==3:
return 0
else:
x=baseorder(num)
return (2**x)*((num-2**x+1)%2)+function(num-2**x)
def xorconv(n,X,Y):
if n==0:
res=[(X[0]*Y[0])%mod]
return res
x=[digit[i]+X[i+2**(n-1)] for i in range(2**(n-1))]
y=[Y[i]+Y[i+2**(n-1)] for i in range(2**(n-1))]
z=[digit[i]-X[i+2**(n-1)] for i in range(2**(n-1))]
w=[Y[i]-Y[i+2**(n-1)] for i in range(2**(n-1))]
res1=xorconv(n-1,x,y)
res2=xorconv(n-1,z,w)
former=[(res1[i]+res2[i])*inv for i in range(2**(n-1))]
latter=[(res1[i]-res2[i])*inv for i in range(2**(n-1))]
former=list(map(lambda x:x%mod,former))
latter=list(map(lambda x:x%mod,latter))
return former+latter
def merge_sort(A,B):
pos_A,pos_B = 0,0
n,m = len(A),len(B)
res = []
while pos_A < n and pos_B < m:
a,b = A[pos_A],B[pos_B]
if a < b:
res.append(a)
pos_A += 1
else:
res.append(b)
pos_B += 1
res += A[pos_A:]
res += B[pos_B:]
return res
class UnionFindVerSize():
def __init__(self, N):
self._parent = [n for n in range(0, N)]
self._size = [1] * N
self.group = N
def find_root(self, x):
if self._parent[x] == x: return x
self._parent[x] = self.find_root(self._parent[x])
stack = [x]
while self._parent[stack[-1]]!=stack[-1]:
stack.append(self._parent[stack[-1]])
for v in stack:
self._parent[v] = stack[-1]
return self._parent[x]
def unite(self, x, y):
gx = self.find_root(x)
gy = self.find_root(y)
if gx == gy: return
self.group -= 1
if self._size[gx] < self._size[gy]:
self._parent[gx] = gy
self._size[gy] += self._size[gx]
else:
self._parent[gy] = gx
self._size[gx] += self._size[gy]
def get_size(self, x):
return self._size[self.find_root(x)]
def is_same_group(self, x, y):
return self.find_root(x) == self.find_root(y)
class WeightedUnionFind():
def __init__(self,N):
self.parent = [i for i in range(N)]
self.size = [1 for i in range(N)]
self.val = [0 for i in range(N)]
self.flag = True
self.edge = [[] for i in range(N)]
def dfs(self,v,pv):
stack = [(v,pv)]
new_parent = self.parent[pv]
while stack:
v,pv = stack.pop()
self.parent[v] = new_parent
for nv,w in self.edge[v]:
if nv!=pv:
self.val[nv] = self.val[v] + w
stack.append((nv,v))
def unite(self,x,y,w):
if not self.flag:
return
if self.parent[x]==self.parent[y]:
self.flag = (self.val[x] - self.val[y] == w)
return
if self.size[self.parent[x]]>self.size[self.parent[y]]:
self.edge[x].append((y,-w))
self.edge[y].append((x,w))
self.size[x] += self.size[y]
self.val[y] = self.val[x] - w
self.dfs(y,x)
else:
self.edge[x].append((y,-w))
self.edge[y].append((x,w))
self.size[y] += self.size[x]
self.val[x] = self.val[y] + w
self.dfs(x,y)
class Dijkstra():
class Edge():
def __init__(self, _to, _cost):
self.to = _to
self.cost = _cost
def __init__(self, V):
self.G = [[] for i in range(V)]
self._E = 0
self._V = V
@property
def E(self):
return self._E
@property
def V(self):
return self._V
def add_edge(self, _from, _to, _cost):
self.G[_from].append(self.Edge(_to, _cost))
self._E += 1
def shortest_path(self, s):
import heapq
que = []
d = [10**15] * self.V
d[s] = 0
heapq.heappush(que, (0, s))
while len(que) != 0:
cost, v = heapq.heappop(que)
if d[v] < cost: continue
for i in range(len(self.G[v])):
e = self.G[v][i]
if d[e.to] > d[v] + e.cost:
d[e.to] = d[v] + e.cost
heapq.heappush(que, (d[e.to], e.to))
return d
#Z[i]:length of the longest list starting from S[i] which is also a prefix of S
#O(|S|)
def Z_algorithm(s):
N = len(s)
Z_alg = [0]*N
Z_alg[0] = N
i = 1
j = 0
while i < N:
while i+j < N and s[j] == s[i+j]:
j += 1
Z_alg[i] = j
if j == 0:
i += 1
continue
k = 1
while i+k < N and k + Z_alg[k]<j:
Z_alg[i+k] = Z_alg[k]
k += 1
i += k
j -= k
return Z_alg
class BIT():
def __init__(self,n,mod=0):
self.BIT = [0]*(n+1)
self.num = n
self.mod = mod
def query(self,idx):
res_sum = 0
mod = self.mod
while idx > 0:
res_sum += self.BIT[idx]
if mod:
res_sum %= mod
idx -= idx&(-idx)
return res_sum
#Ai += x O(logN)
def update(self,idx,x):
mod = self.mod
while idx <= self.num:
self.BIT[idx] += x
if mod:
self.BIT[idx] %= mod
idx += idx&(-idx)
return
class dancinglink():
def __init__(self,n,debug=False):
self.n = n
self.debug = debug
self._left = [i-1 for i in range(n)]
self._right = [i+1 for i in range(n)]
self.exist = [True for i in range(n)]
def pop(self,k):
if self.debug:
assert self.exist[k]
L = self._left[k]
R = self._right[k]
if L!=-1:
if R!=self.n:
self._right[L],self._left[R] = R,L
else:
self._right[L] = self.n
elif R!=self.n:
self._left[R] = -1
self.exist[k] = False
def left(self,idx,k=1):
if self.debug:
assert self.exist[idx]
res = idx
while k:
res = self._left[res]
if res==-1:
break
k -= 1
return res
def right(self,idx,k=1):
if self.debug:
assert self.exist[idx]
res = idx
while k:
res = self._right[res]
if res==self.n:
break
k -= 1
return res
class SparseTable():
def __init__(self,A,merge_func,ide_ele):
N=len(A)
n=N.bit_length()
self.table=[[ide_ele for i in range(n)] for i in range(N)]
self.merge_func=merge_func
for i in range(N):
self.table[i][0]=A[i]
for j in range(1,n):
for i in range(0,N-2**j+1):
f=self.table[i][j-1]
s=self.table[i+2**(j-1)][j-1]
self.table[i][j]=self.merge_func(f,s)
def query(self,s,t):
b=t-s+1
m=b.bit_length()-1
return self.merge_func(self.table[s][m],self.table[t-2**m+1][m])
class BinaryTrie:
class node:
def __init__(self,val):
self.left = None
self.right = None
self.max = val
def __init__(self):
self.root = self.node(-10**15)
def append(self,key,val):
pos = self.root
for i in range(29,-1,-1):
pos.max = max(pos.max,val)
if key>>i & 1:
if pos.right is None:
pos.right = self.node(val)
pos = pos.right
else:
pos = pos.right
else:
if pos.left is None:
pos.left = self.node(val)
pos = pos.left
else:
pos = pos.left
pos.max = max(pos.max,val)
def search(self,M,xor):
res = -10**15
pos = self.root
for i in range(29,-1,-1):
if pos is None:
break
if M>>i & 1:
if xor>>i & 1:
if pos.right:
res = max(res,pos.right.max)
pos = pos.left
else:
if pos.left:
res = max(res,pos.left.max)
pos = pos.right
else:
if xor>>i & 1:
pos = pos.right
else:
pos = pos.left
if pos:
res = max(res,pos.max)
return res
def solveequation(edge,ans,n,m):
#edge=[[to,dire,id]...]
x=[0]*m
used=[False]*n
for v in range(n):
if used[v]:
continue
y = dfs(v)
if y!=0:
return False
return x
def dfs(v):
used[v]=True
r=ans[v]
for to,dire,id in edge[v]:
if used[to]:
continue
y=dfs(to)
if dire==-1:
x[id]=y
else:
x[id]=-y
r+=y
return r
class Matrix():
mod=10**9+7
def set_mod(m):
Matrix.mod=m
def __init__(self,L):
self.row=len(L)
self.column=len(L[0])
self._matrix=L
for i in range(self.row):
for j in range(self.column):
self._matridigit[i][j]%=Matrix.mod
def __getitem__(self,item):
if type(item)==int:
raise IndexError("you must specific row and column")
elif len(item)!=2:
raise IndexError("you must specific row and column")
i,j=item
return self._matridigit[i][j]
def __setitem__(self,item,val):
if type(item)==int:
raise IndexError("you must specific row and column")
elif len(item)!=2:
raise IndexError("you must specific row and column")
i,j=item
self._matridigit[i][j]=val
def __add__(self,other):
if (self.row,self.column)!=(other.row,other.column):
raise SizeError("sizes of matrixes are different")
res=[[0 for j in range(self.column)] for i in range(self.row)]
for i in range(self.row):
for j in range(self.column):
res[i][j]=self._matridigit[i][j]+other._matridigit[i][j]
res[i][j]%=Matrix.mod
return Matrix(res)
def __sub__(self,other):
if (self.row,self.column)!=(other.row,other.column):
raise SizeError("sizes of matrixes are different")
res=[[0 for j in range(self.column)] for i in range(self.row)]
for i in range(self.row):
for j in range(self.column):
res[i][j]=self._matridigit[i][j]-other._matridigit[i][j]
res[i][j]%=Matrix.mod
return Matrix(res)
def __mul__(self,other):
if type(other)!=int:
if self.column!=other.row:
raise SizeError("sizes of matrixes are different")
res=[[0 for j in range(other.column)] for i in range(self.row)]
for i in range(self.row):
for j in range(other.column):
temp=0
for k in range(self.column):
temp+=self._matridigit[i][k]*other._matrix[k][j]
res[i][j]=temp%Matrix.mod
return Matrix(res)
else:
n=other
res=[[(n*self._matridigit[i][j])%Matrix.mod for j in range(self.column)] for i in range(self.row)]
return Matrix(res)
def __pow__(self,m):
if self.column!=self.row:
raise MatrixPowError("the size of row must be the same as that of column")
n=self.row
res=Matrix([[int(i==j) for i in range(n)] for j in range(n)])
while m:
if m%2==1:
res=res*self
self=self*self
m//=2
return res
def __str__(self):
res=[]
for i in range(self.row):
for j in range(self.column):
res.append(str(self._matridigit[i][j]))
res.append(" ")
res.append("\n")
res=res[:len(res)-1]
return "".join(res)
from collections import deque
class Dinic:
def __init__(self, N):
self.N = N
self.G = [[] for i in range(N)]
def add_edge(self, fr, to, cap):
forward = [to, cap, None]
forward[2] = backward = [fr, 0, forward]
self.G[fr].append(forward)
self.G[to].append(backward)
def add_multi_edge(self, v1, v2, cap1, cap2):
edge1 = [v2, cap1, None]
edge1[2] = edge2 = [v1, cap2, edge1]
self.G[v1].append(edge1)
self.G[v2].append(edge2)
def bfs(self, s, t):
self.level = level = [None]*self.N
deq = deque([s])
level[s] = 0
G = self.G
while deq:
v = deq.popleft()
lv = level[v] + 1
for w, cap, _ in G[v]:
if cap and level[w] is None:
level[w] = lv
deq.append(w)
return level[t] is not None
def dfs(self, v, t, f):
if v == t:
return f
level = self.level
for e in self.it[v]:
w, cap, rev = e
if cap and level[v] < level[w]:
d = self.dfs(w, t, min(f, cap))
if d:
e[1] -= d
rev[1] += d
return d
return 0
def flow(self, s, t):
flow = 0
INF = 10**9 + 7
G = self.G
while self.bfs(s, t):
*self.it, = map(iter, self.G)
f = INF
while f:
f = self.dfs(s, t, INF)
flow += f
return flow
class SegmentTree:
def __init__(self, init_val, segfunc, ide_ele):
n = len(init_val)
self.segfunc = segfunc
self.ide_ele = ide_ele
self.num = 1 << (n - 1).bit_length()
self.tree = [ide_ele] * 2 * self.num
self.size = n
for i in range(n):
self.tree[self.num + i] = init_val[i]
for i in range(self.num - 1, 0, -1):
self.tree[i] = self.segfunc(self.tree[2 * i], self.tree[2 * i + 1])
def update(self, k, x):
k += self.num
self.tree[k] = x
while k > 1:
k >>= 1
self.tree[k] = self.segfunc(self.tree[2*k],self.tree[2*k+1])
def query(self, l, r):
if r==self.size:
r = self.num
res = self.ide_ele
l += self.num
r += self.num
right = []
while l < r:
if l & 1:
res = self.segfunc(res, self.tree[l])
l += 1
if r & 1:
right.append(self.tree[r-1])
l >>= 1
r >>= 1
for y in right[::-1]:
res = self.segfunc(res,y)
return res
import sys,random,bisect
from collections import deque,defaultdict
from heapq import heapify,heappop,heappush
from itertools import permutations
from math import gcd,log
input = lambda :sys.stdin.readline().rstrip()
mi = lambda :map(int,input().split())
li = lambda :list(mi())
N = int(input())
edge = [[] for i in range(N)]
E = []
for i in range(N-1):
a,b,c = mi()
edge[a-1].append((b-1,c))
edge[b-1].append((a-1,c))
E.append((c,a-1,b-1))
E.sort(key=lambda x:-x[0])
if N==2:
exit(print(0))
parent = [-1] * N
depth = [0] * N
deq = deque([0])
while deq:
v = deq.popleft()
for nv,c in edge[v]:
if parent[v]!=nv:
parent[nv] = v
depth[nv] = depth[v] + 1
deq.append(nv)
def cond(k):
u = E[0][1]
v = E[0][2]
S = set([u,v])
if depth[u] < depth[v]:
u = v
for i in range(1,k+1):
c,a,b = E[i]
if depth[u] < depth[a]:
u = a
if depth[u] < depth[b]:
u = b
S.add(a)
S.add(b)
tmp_parent = [-1] * N
tmp_depth = [0] * N
deq = deque([u])
while deq:
v = deq.popleft()
for nv,c in edge[v]:
if tmp_parent[v]!=nv:
tmp_parent[nv] = v
tmp_depth[nv] = tmp_depth[v] + 1
deq.append(nv)
v = u
for a in S:
if tmp_depth[v] < tmp_depth[a]:
v = a
T = set([v,u])
while v!=u:
T.add(tmp_parent[v])
v = tmp_parent[v]
for a in S:
if a not in T:
return False,-1
return True,u
ok = 0
ng = N-1
root = E[0][1]
while ng-ok>1:
mid = (ok+ng)//2
f,r = cond(mid)
if f:
root = r
ok = mid
else:
ng = mid
parent = [(-1,-1)] * N
depth = [0] * N
deq = deque([root])
while deq:
v = deq.popleft()
for nv,c in edge[v]:
if parent[v][0]!=nv:
parent[nv] = (v,c)
depth[nv] = depth[v] + 1
deq.append(nv)
res = E[1][0]
ancestor,child = E[0][1],E[0][2]
if depth[ancestor] > depth[child]:
ancestor,child = child,ancestor
C = E[0][0]
for i in range(1,ok+1):
c,u,v = E[i]
if depth[u] > depth[v]:
u,v = v,u
if depth[u] < depth[ancestor]:
while ancestor!=u:
ancestor,d = parent[ancestor]
C = min(C,d)
if depth[child] < depth[v]:
tmp = v
while tmp!=child:
tmp,d = parent[tmp]
C = min(C,d)
child = v
if i==N-2:
tmp = E[0][0] - C
else:
tmp = max(E[0][0]-C,E[i+1][0])
res = min(res,tmp)
print(res)