Submission #428997

#	Time	Username	Problem	Language	Result	Execution time	Memory
428997		cfalas	Power Plant (JOI20_power)	C++14	100 / 100	456 ms	30456 KiB

power

#include<bits/stdc++.h>
using namespace std;
#define mp make_pair
#define INF 10000000
#define MOD 1000000007
#define MID ((l+r)/2)
#define HASHMOD 2305843009213693951
#define ll long long
#define ull unsigned long long
#define F first
#define S second
typedef pair<ll, ll> ii;
typedef pair<ii, int> iii;
typedef vector<int> vi;
typedef vector<ii> vii;
typedef map<int, int> mii;

#define EPS 1e-6
#define FOR(i,n) for(int i=0;i<((int)(n));i++)
#define FORi(i,a,b) for(int i=((int)(a));i<((int)(b));i++)
#define FOA(v, a) for(auto v : a)

int t, n;
vi a, b;

vector<vi> adj;
string x;

int cnt[300000];
int dfsc(int s, int p=-1){
	cnt[s] = (x[s-1]=='1');
	FOA(v,adj[s]) if(v!=p) cnt[s] += dfsc(v,s);
	return cnt[s];
}

int dp[300000];

int dfs(int s, int p=-1){
	if(dp[s]!=-1) return dp[s];
	int ans2=0;
	if(x[s-1]=='1') ans2 = 1;
	int ans3 = 0;
	if(x[s-1]=='1') ans3--;
	FOA(v, adj[s]){
		if(v==p) continue;
		//cout<<s<<" going to "<<v<<endl;
		//if(x[s-1]=='1') ans2 = max(ans2, 1+dfs(v,s));
		ans3 += dfs(v,s);
	}
	ans2 = max(ans2, ans3);
	dp[s] = ans2;
	return ans2;
}

int anss[300000];
int ans(int s, int p=-1){
	int ans2=1;
	int ans3 = 0;
	if(x[s-1]=='1') ans3--;
	FOA(v, adj[s]){
		if(v==p) continue;
		if(x[s-1]=='1') ans2 = max(ans2, 1+dfs(v));
		ans3 += dfs(v);
		ans(v,s);
	}
	ans2 = max(ans2, ans3);
	anss[s] = ans2;
	return ans2;

}

int main(){
	cin>>n;
	adj.assign(n+1, vi());
	FOR(i,n+1) dp[i] = -1;
	FOR(i,n-1){
		int a, b;
		cin>>a>>b;
		adj[a].push_back(b);
		adj[b].push_back(a);
	}
	cin>>x;
	dfsc(1);
	dfs(1);
	int xx = ans(1);
	FORi(i,1,n+1){
		xx = max(xx, anss[i]);
		//cout<<i<<" "<<dfs(i)<<endl;
	}
	cout<<xx<<endl;

}

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