Submission #763084

#	Time	Username	Problem	Language	Result	Execution time	Memory
763084		vjudge1	Power Plant (JOI20_power)	C++14	47 / 100	110 ms	24908 KiB

power

//#pragma GCC optimize("Ofast,unroll-loops")
//#pragma GCC target("bmi,bmi2,lzcnt,popcnt")
//#pragma GCC target("avx2,popcnt,lzcnt,abm,bmi,bmi2,fma,tune=native")
//#pragma expected_value
//#pragma isolated_call
//#pragma disjoint

#include<bits/stdc++.h>
//#include <ext/pb_ds/assoc_container.hpp>

//using namespace __gnu_pbds;
using namespace std;

//#define int long long
//#define double long double
#define Fi first
#define Se second
#define Rep(i,a,b) for (int i=a;i<=b;++i)
#define Repu(i,b,a) for (int i=b;i>=a;--i)
#define pb push_back
#define ms(a,i) memset(a,i,sizeof(a))
#define sz size()
#define mp make_pair
#define endl '\n'
#define sef setprecision(12)<<fixed
#define cer cout<<"cak"<<endl;

typedef pair<int,int> ii;
typedef vector<int> vi;
typedef vector<double> va;
typedef vector<ii> vii;
typedef vector<vi> vvi;
typedef vector<va> vva;

//const double EPS=1e-9;
const double PI=acos(-1);
//const int oo=1e18;
const int MN=2e5+5;
const int mod=1e9+7;

using cd=complex<double>;

//typedef tree<int,null_type,less<int>,rb_tree_tag, tree_order_statistics_node_update> index_set;

int n;
vi adj[MN];

char s[MN];

int siz[MN];

void dfs(int u,int pre) {
	int sum = 0;
	for(int v:adj[u]) {
		if(v==pre) continue;
		dfs(v,u);
		sum += siz[v];
	}

	if(s[u]=='1') {
		sum--;
		siz[u] = max(1,sum);
	}
	else {
		siz[u] = sum;
	}
}

void solve(int u) {
	for(int v:adj[u]) {
		dfs(v,u);
		siz[u] = max(siz[u], siz[v]);
	}
	siz[u]++;
}

void process(int u) {
	for(int v:adj[u]) {
		dfs(v,u);
		siz[u] += siz[v];
	}
}

signed main() {
	//freopen(".inp","r",stdin); freopen(".out","w",stdout);

	ios_base::sync_with_stdio(false);
	cin.tie(NULL);
	cout.tie(NULL);

	cin>>n;
	Rep(i,1,n-1) {
		int u,v; cin>>u>>v;
		adj[u].pb(v); adj[v].pb(u);
	}

	Rep(i,1,n) cin>>s[i];

	int ans=0;

	if(n<=2000) {
		Rep(i,1,n) {
			if(s[i]=='1') {
				Rep(i,1,n) siz[i] = 0;
				solve(i);
				//cout<<"Root at "<<i<<endl;
				//Rep(i,1,n) cout<<siz[i]<<" ";
				//cout<<endl;
				ans=max(ans,siz[i]);
			}
			else {
				Rep(i,1,n) siz[i] = 0;
				process(i);
				ans=max(ans,siz[i]);
			}
		}

		cout<<ans;

		return 0;
	}

	Rep(i,1,n) {
		if(s[i]=='1') {
			Rep(i,1,n) siz[i] = 0;
			solve(i);
			ans=max(ans,siz[i]);
			break;
		}
	}

	Rep(i,1,n) {
		if(s[i]=='0') {
			Rep(i,1,n) siz[i] = 0;
			process(i);
			ans=max(ans,siz[i]);
			break;
		}
	}

	cout<<ans;
}

• Subtask 1: 6 / 6
• Subtask 2: 41 / 41
• Subtask 3: 0 / 53