Submission #854475

#	Time	Username	Problem	Language	Result	Execution time	Memory
854475		Wansur	Closing Time (IOI23_closing)	C++17	0 / 100	1072 ms	32456 KiB

closing

#include <vector>
#include<bits/stdc++.h>
#define f first
#define s second
 
using namespace std;
const int mx=2e5+12;
 
vector<pair<int,long long>> g[mx];
long long d1[mx];
long long d2[mx];
long long n,k;
 
void dfs(int v,int p,bool ok){
	for(auto To:g[v]){
		int to=To.f,w=To.s;
		if(to==p){
			continue;
		}
		if(ok){
			d2[to]=d2[v]+w;
		}
		else{
			d1[to]=d1[v]+w;
		}
		dfs(to,v,ok);
	}
}
 
int max_score(int N, int x, int y, long long K, std::vector<int> U,std::vector<int> V, std::vector<int> W){
	n=N,k=K;
	for(int i=0;i<n;i++){
		g[i].clear();
		d1[i]=d2[i]=0;
	}
	for(int i=0;i<n-1;i++){
		g[V[i]].push_back({U[i],W[i]});
		g[U[i]].push_back({V[i],W[i]});
	}
	dfs(x,-1,0);
	dfs(y,-1,1);
	long long ans=0;
	for(int pos=x;pos<y;pos++){
		vector<long long> v;
		for(int i=0;i<n;i++){
			if(i<=pos){
				v.push_back(d1[i]);
			}
			else{
				v.push_back(d2[i]);
			}
		}
		sort(v.begin(),v.end());
		long long sum=0,cnt=0;
		for(long long x:v){
			if(sum+x<=k){
				sum+=x;
				cnt++;
			}
		}
		ans=max(ans,cnt);
	}
	for(int l=0;l<=x;l++){
		for(int r=y;r<n;r++){
			long long sum=0,cnt=0;
			for(int i=0;i<n;i++){
				long long t=0;
				if(x<=i && i<=y){
					t=max(d1[i],d2[i]);
					cnt+=2;
				}
				if(i<x){
					t=d1[i];
					cnt++;
				}
				if(i>y){
					cnt++;
					t=d2[i];
				}
				sum+=t;
			}
			if(sum<=k){
				ans=max(ans,cnt);
			}
			
		}
	}
	long long cnt=0,sum=0;
	vector<long long> v;
	for(int i=0;i<n;i++){
		v.push_back(d1[i]);
	}
	sort(v.begin(),v.end());
	for(long long x:v){
		if(sum+x<=k){
			sum+=x;
			cnt++;
		}
	}
	ans=max(ans,cnt);
	cnt=sum=0;
	v.clear();
	for(int i=0;i<n;i++){
		v.push_back(d2[i]);
	}
	sort(v.begin(),v.end());
	for(long long x:v){
		if(sum+x<=k){
			sum+=x;
			cnt++;
		}
	}
	ans=max(ans,cnt);
	return ans;
}

• Subtask 0: 0 / 0
• Subtask 1: 0 / 8
• Subtask 2: 0 / 9
• Subtask 3: 0 / 12
• Subtask 4: 0 / 14
• Subtask 5: 0 / 9
• Subtask 6: 0 / 11
• Subtask 7: 0 / 10
• Subtask 8: 0 / 10
• Subtask 9: 0 / 17