제출 #1266139

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1266139		PlayVoltz	Cat Exercise (JOI23_ho_t4)	C++20	0 / 100	1 ms	320 KiB

Main

#include <cstdio>
#include <stdio.h>
#include <stdbool.h>
#include <iostream>
#include <map>
#include <vector>
#include <climits>
#include <stack>
#include <string>
#include <queue>
#include <algorithm>
#include <set>
#include <unordered_set>
#include <unordered_map>
#include <cmath>
#include <cctype>
#include <bitset>
#include <iomanip>
#include <cstring>
#include <numeric>
#include <cassert>
using namespace std;
 
#define int long long
#define pii pair<int, int>
#define mp make_pair
#define pb push_back
#define fi first
#define se second

vector<int> depth, dsu, vect;
vector<vector<int> > graph, twok;

void dfs(int node, int p, int d){
	depth[node]=d;
	twok[node][0]=p;
	for (int i=1; i<20; ++i)twok[node][i]=twok[twok[node][i-1]][i-1];
	for (auto num:graph[node])if (num!=p)dfs(num, node, d+1);
}

int lca(int a, int b){
	if (depth[a]<depth[b])swap(a, b);
	for (int i=0, k=depth[a]-depth[b]; i<20; ++i)if (k&(1<<i))a=twok[a][i];
	if (a==b)return a;
	for (int i=19; i>=0; --i)if (twok[a][i]!=twok[b][i])a=twok[a][i], b=twok[b][i];
	return twok[a][0];
}

int fp(int a){
	if (dsu[a]==-1)return a;
	return dsu[a]=fp(dsu[a]);
}

void merge(int a, int b){
	a=fp(a), b=fp(b);
	if (a==b)return;
	if (vect[a]<vect[b])dsu[a]=b;
	else dsu[b]=a;
}

int dist(int a, int b){
	return depth[a]+depth[b]-2*depth[lca(a, b)];
}

int32_t main(){
	ios_base::sync_with_stdio(0);
	cin.tie(0);
	cout.tie(0);
	int n, a, b;
	cin>>n;
	dsu.resize(n+1, -1);
	graph.resize(n+1);
	depth.resize(n+1);
	vect.resize(n+1);
	twok.resize(20, vector<int>(n+1));
	vector<int> ord(n), dp(n+1, 0);
	for (int i=1; i<=n; ++i)cin>>vect[i], ord[vect[i]-1]=i;
	for (int i=1; i<n; ++i){
		cin>>a>>b;
		graph[a].pb(b);
		graph[b].pb(a);
	}
	dfs(1, 1, 0);
	for (auto node:ord)for (auto num:graph[node])if (vect[node]>vect[num])dp[node]=max(dp[node], dp[fp(num)]+dist(fp(num), node)), merge(num, node);
	cout<<dp[ord.back()];
}

• Subtask 1: 0 / 7
• Subtask 2: 0 / 7
• Subtask 3: 0 / 7
• Subtask 4: 0 / 10
• Subtask 5: 0 / 20
• Subtask 6: 0 / 23
• Subtask 7: 0 / 26