結果

問題 No.2072 Anatomy
コンテスト
ユーザー vwxyz
提出日時 2023-11-29 20:59:29
言語 Python3
(3.13.1 + numpy 2.2.1 + scipy 1.14.1)
結果
AC  
実行時間 1,189 ms / 2,000 ms
コード長 4,869 bytes
コンパイル時間 214 ms
コンパイル使用メモリ 13,184 KB
実行使用メモリ 60,892 KB
最終ジャッジ日時 2024-09-26 13:39:21
合計ジャッジ時間 23,356 ms
ジャッジサーバーID
（参考情報） 		judge2 / judge3
このコードへのチャレンジ
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ファイルパターン 結果
sample AC * 2
other AC * 27
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 #
raw source code 

import bisect
import copy
import decimal
import fractions
import heapq
import itertools
import math
import random
import sys
import time
from collections import Counter,deque,defaultdict
from functools import lru_cache,reduce
from heapq import heappush,heappop,heapify,heappushpop,_heappop_max,_heapify_max
def _heappush_max(heap,item):
    heap.append(item)
    heapq._siftdown_max(heap, 0, len(heap)-1)
def _heappushpop_max(heap, item):
    if heap and item < heap[0]:
        item, heap[0] = heap[0], item
        heapq._siftup_max(heap, 0)
    return item
from math import gcd as GCD
read=sys.stdin.read
readline=sys.stdin.readline
readlines=sys.stdin.readlines
write=sys.stdout.write
#import pypyjit
#pypyjit.set_param('max_unroll_recursion=-1')
#sys.set_int_max_str_digits(10**9)

class UnionFind:
    def __init__(self,N,label=None,f=None,weighted=False,rollback=False):
        self.N=N
        self.parents=[None]*self.N
        self.size=[1]*self.N
        self.roots={i for i in range(self.N)}
        self.label=label
        if self.label!=None:
            self.label=[x for x in label]
        self.f=f
        self.weighted=weighted
        if self.weighted:
            self.weight=[0]*self.N
        self.rollback=rollback
        if self.rollback:
            self.operate_list=[]
            self.operate_set=[]

    def Find(self,x):
        stack=[]
        while self.parents[x]!=None:
            stack.append(x)
            x=self.parents[x]
        if not self.rollback:
            if self.weighted:
                w=0
                for y in stack[::-1]:
                    self.parents[y]=x
                    w+=self.weight[y]
                    self.weight[y]=w
            else:
                for y in stack[::-1]:
                    self.parents[y]=x
        return x

    def Union(self,x,y,w=None):
        root_x=self.Find(x)
        root_y=self.Find(y)
        if self.rollback:
            self.operate_list.append([])
            self.operate_set.append([])
        if root_x==root_y:
            if self.weighted:
                if self.weight[y]-self.weight[x]==w:
                    return True
                else:
                    return False
        else:
            if self.size[root_x]<self.size[root_y]:
                x,y=y,x
                root_x,root_y=root_y,root_x
                if self.weighted:
                    w=-w
            if self.rollback:
                self.operate_list[-1].append((self.parents,root_y,self.parents[root_y]))
                self.operate_list[-1].append((self.size,root_x,self.size[root_x]))
                self.operate_set[-1].append(root_y)
                if self.label!=None:
                    self.operate_list[-1]((self.label,root_x,self.label[root_x]))
                if self.weighted:
                    self.operate_list[-1].append((self.weight,root_y,self.weight[root_y]))
            self.parents[root_y]=root_x
            self.size[root_x]+=self.size[root_y]
            self.roots.remove(root_y)
            if self.label!=None:
                self.label[root_x]=self.f(self.label[root_x],self.label[root_y])
            if self.weighted:
                self.weight[root_y]=w+self.weight[x]-self.weight[y]

    def Size(self,x):
        return self.size[self.Find(x)]

    def Same(self,x,y):
        return self.Find(x)==self.Find(y)

    def Label(self,x):
        return self.label[self.Find(x)]

    def Weight(self,x,y):
        root_x=self.Find(x)
        root_y=self.Find(y)
        if root_x!=root_y:
            return None
        return self.weight[y]-self.weight[x]

    def Roots(self):
        return list(self.roots)

    def Linked_Components_Count(self):
        return len(self.roots)

    def Linked_Components(self):
        linked_components=defaultdict(list)
        for x in range(self.N):
            linked_components[self.Find(x)].append(x)
        return linked_components
    
    def Rollback(self):
        assert self.rollback
        if self.operate_list:
            for lst,x,v in self.operate_list.pop():
                lst[x]=v
            for x in self.operate_set.pop():
                self.roots.add(x)            
            return True
        else:
            return False
        

    def __str__(self):
        linked_components=defaultdict(list)
        for x in range(self.N):
            linked_components[self.Find(x)].append(x)
        return "\n".join(f"{r}: {linked_components[r]}" for r in sorted(list(linked_components.keys())))

N,M=map(int,readline().split())
edges=[]
for m in range(M):
    u,v=map(int,readline().split())
    u-=1;v-=1
    edges.append((u,v))
dp=[0]*N
UF=UnionFind(N)
for u,v in edges[::-1]:
    u=UF.Find(u)
    v=UF.Find(v)
    if u==v:
        dp[u]+=1
    else:
        UF.Union(u,v)
        p=UF.Find(u)
        dp[p]=max(dp[u],dp[v])+1
ans=max(dp)
print(ans)
0