Submission #552138

#	Time	Username	Problem	Language	Result	Execution time	Memory
552138		CSQ31	Dreaming (IOI13_dreaming)	C++17	22 / 100	1083 ms	11724 KiB

dreaming

#include "dreaming.h"
#include <bits/stdc++.h>
using namespace std;
const int MAXN = 1e5+1;
vector<pair<int,int>>adj[MAXN];
bool vis[MAXN];
int dep[MAXN],p[MAXN];
vector<int>cc;
int mn = 2e9,ans = 0;
void dfs(int v,int u){
	vis[v] = 1;
	cc.push_back(v);
	for(auto x:adj[v]){
		if(x.first != u){
			dfs(x.first,v);
			dep[v] = max(dep[v],dep[x.first] + x.second);
			
		}
	}
}
void dfs2(int v,int u){
	for(auto x:adj[v]){
		if(x.first != u){
			dfs2(x.first,v);
			dep[v] = max(dep[v],dep[x.first] + x.second);
			
		}
	}
}
void get(int v,int u){
	multiset<int,greater<int>>s;
	s.insert(p[v]);
	for(auto x:adj[v]){
		if(x.first == u)continue;
		s.insert(dep[x.first] + x.second);
	}
	int mx = max(p[v],dep[v]);
	mn = min(mx,mn);
	for(auto x:adj[v]){
		if(x.first == u)continue;
		s.erase(s.find(dep[x.first] + x.second));
		p[x.first] = *s.begin() + x.second;
		get(x.first,v);
		s.insert(dep[x.first] + x.second);
	}
	
}
int travelTime(int N, int M, int L, int A[], int B[], int T[]) {
	for(int i=0;i<M;i++){
		adj[A[i]].push_back({B[i],T[i]});
		adj[B[i]].push_back({A[i],T[i]});
	}
	vector<int>v;
	for(int i=0;i<N;i++){
		if(!vis[i]){
			cc.clear();
			dfs(i,-1);
			mn = 1e9;
			for(int x:cc){
				for(int j=0;j<N;j++)dep[j] = p[j] = 0;
				dfs2(x,-1);
				mn = min(mn,dep[x]);
				ans = max(ans,dep[x]);
			}
			
			v.push_back(mn);
			//cout<<i<<" "<<mn<<'\n';
		}
	}
	//for(int i=0;i<N;i++)cout<<dep[i]<<" ";
	//cout<<'\n';
	//for(int i=0;i<N;i++)cout<<p[i]<<" ";
	//cout<<'\n';
	sort(v.begin(),v.end(),greater<int>());
	if(v.size()>=2)ans = max(ans,v[0] + v[1] + L);
	if(v.size()>=3)ans = max(ans,v[1] + v[2] + 2*L);
	return ans;
}
/*
int main(){
	int n,m,l;
	cin>>n>>m>>l;
	int a[m],b[m],t[m];
	for(int i=0;i<m;i++)cin>>a[i]>>b[i]>>t[i];
	cout<<travelTime(n,m,l,a,b,t);
	
}*/

• Subtask 1: 0 / 14
• Subtask 2: 10 / 10
• Subtask 3: 0 / 23
• Subtask 4: 0 / 18
• Subtask 5: 12 / 12
• Subtask 6: 0 / 23