Submission #430860

#	Time	Username	Problem	Language	Result	Execution time	Memory
430860		errorgorn	Friend (IOI14_friend)	C++17	27 / 100	9 ms	11596 KiB

friend

//雪花飄飄北風嘯嘯
//天地一片蒼茫

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#include <ext/rope>
using namespace std;
using namespace __gnu_pbds;
using namespace __gnu_cxx;
#define ll long long
#define ii pair<ll,ll>
#define iii pair<ii,ll>
#define fi first
#define se second
#define endl '\n'
#define debug(x) cout << #x << ": " << x << endl

#define pub push_back
#define pob pop_back
#define puf push_front
#define pof pop_front
#define lb lower_bound
#define ub upper_bound

#define rep(x,start,end) for(auto x=(start)-((start)>(end));x!=(end)-((start)>(end));((start)<(end)?x++:x--))
#define all(x) (x).begin(),(x).end()
#define sz(x) (int)(x).size()

#define indexed_set tree<ll,null_type,less<ll>,rb_tree_tag,tree_order_statistics_node_update>
//change less to less_equal for non distinct pbds, but erase will bug

mt19937 rng(chrono::system_clock::now().time_since_epoch().count());

const int NORMAL=0; //normal friendship
const int COPY1=1; //both itself and parent can be on
const int COPY2=2; //either itself or parent must be off
const int DUP=3; //copy of certain node

int n;
int arr[100005];

vector<ii> al[200005];
int val[200005];
int id[100005];
int IDX=1;

int memo[200005][2][2][2];

//for a normal friendship edge, for the guy to be toggled
//everyone connected by copy/dup edges must be toggled off
//for copy2 edges, all subtrees with copy2 edge but all be off
//if you are on, all parents traversed by copy edges shld be togglable

//states:
// b1: anyone in your copy CC toggled
// b2: anyone in copy1 CC toggled
// b3: are you toggled

//if there is someone in your copy CC toggled
//anyone connected by normal edges cannot have their copy CC toggled

//you also need to be same toggle as duplicate if yourself if it exists

int dp(int i,int b1,int b2,int b3){
	if (memo[i][b1][b2][b3]!=-1) return memo[i][b1][b2][b3];
	
	int res=0;
	if (b3) res+=val[i];
	if (b3 && (!b1 || !b2)) return memo[i][b1][b2][b3]=-1e9;
	
	for (auto &it:al[i]){
		if (it.se==DUP){
			res+=dp(it.fi,b1,b2,b3);
		}
		if (it.se==NORMAL){
			if (b1) res+=dp(it.fi,0,0,0);
			else{
				int temp=0;
				rep(x,0,2) rep(y,0,2) rep(z,0,2)
					temp=max(temp,dp(it.fi,x,y,z));
					
				res+=temp;
			}
		}
		if (it.se==COPY1){
			res+=max(dp(it.fi,b1,b2,0),dp(it.fi,b1,b2,1));
		}
		if (it.se==COPY2){
			if (b3) res+=dp(it.fi,b1,0,0);
			else{
				int temp=0;
				rep(y,0,2) rep(z,0,2)
					temp=max(temp,dp(it.fi,b1,y,z));
					
				res+=temp;
			}
		}
	}
	
	return memo[i][b1][b2][b3]=res;
}

int findSample(int N,int confidence[],int host[],int protocol[]){
	n=N;
	rep(x,0,n) arr[x]=confidence[x];
	
	id[0]=0;
	
	rep(x,1,n){
		int h=host[x];
		if (protocol[x]==0){
			al[id[h]].pub(ii(IDX,DUP));
			id[h]=IDX++;
			
			al[id[h]].pub(ii(IDX,NORMAL));
			id[x]=IDX++;
		}
		else if (protocol[x]==1){
			al[id[h]].pub(ii(IDX,COPY1));
			id[x]=IDX++;
		}
		else{
			al[id[h]].pub(ii(IDX,DUP));
			id[h]=IDX++;
			
			al[id[h]].pub(ii(IDX,COPY2));
			id[x]=IDX++;
		}
	}
	
	//rep(x,0,n) cout<<id[x]<<" "; cout<<endl;
	rep(x,0,n) val[id[x]]=arr[x];
	
	memset(memo,-1,sizeof(memo));
	
	
	int ans=0;
	rep(x,0,2) rep(y,0,2) rep(z,0,2){
		//cout<<x<<" "<<y<<" "<<z<<" "<<dp(0,x,y,z)<<endl;
		ans=max(ans,dp(0,x,y,z));
	}
	
	return ans;
}

• Subtask 1: 0 / 11
• Subtask 2: 8 / 8
• Subtask 3: 0 / 8
• Subtask 4: 19 / 19
• Subtask 5: 0 / 23
• Subtask 6: 0 / 31