제출 #209711

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
209711		alishahali1382	Zagrade (COI17_zagrade)	C++14	100 / 100	1018 ms	43712 KiB

zagrade

#include <bits/stdc++.h>
#pragma GCC optimize ("O2")
#pragma GCC optimize ("unroll-loops")
//#pragma GCC optimize("no-stack-protector,fast-math")

using namespace std;
typedef long long ll;
typedef long double ld;
typedef pair<int, int> pii;
typedef pair<pii, int> piii;
typedef pair<ll, ll> pll;
#define debug(x) cerr<<#x<<'='<<(x)<<endl;
#define debugp(x) cerr<<#x<<"= {"<<(x.first)<<", "<<(x.second)<<"}"<<endl;
#define debug2(x, y) cerr<<"{"<<#x<<", "<<#y<<"} = {"<<(x)<<", "<<(y)<<"}"<<endl;
#define debugv(v) {cerr<<#v<<" : ";for (auto x:v) cerr<<x<<' ';cerr<<endl;}
#define all(x) x.begin(), x.end()
#define pb push_back
#define kill(x) return cout<<x<<'\n', 0;

const ld eps=1e-7;
const int inf=1000000010;
const ll INF=10000000000000010LL;
const int mod = 1000000007;
const int MAXN = 300010, LOG=20;

int n, m, k, u, v, x, y, t, a, b;
ll ans;
int A[MAXN];
int sz[MAXN];
bool dead[MAXN];
int cnt[MAXN];
vector<int> G[MAXN];

int dfs1(int node, int par){
	sz[node]=1;
	for (int v:G[node]) if (v!=par && !dead[v]) sz[node]+=dfs1(v, node);
	return sz[node];
}

int Centroid(int node, int par, int n){
	for (int v:G[node]) if (v!=par && !dead[v] && 2*sz[v]>n) return Centroid(v, node, n);
	return node;
}

void dfs2(int node, int par, int sum, int mn){
	mn=min(mn, sum+=A[node]);
	//cerr<<"dfs2 "<<node<<" : "<<sum<<' '<<mn<<endl;
	if (mn==sum) ans+=cnt[-sum];
	for (int v:G[node]) if (!dead[v] && v!=par) dfs2(v, node, sum, mn);
}

void dfs3(int node, int par, int sum, int mn){
	sum+=A[node];
	mn=min(A[node], mn+A[node]);
	mn=min(mn, 0);
	if (!mn) cnt[sum]++;
	for (int v:G[node]) if (!dead[v] && v!=par) dfs3(v, node, sum, mn);
}

void Decompose(int node){
	int root=Centroid(node, node, dfs1(node, node));
	dead[root]=1;
	
	fill(cnt, cnt+sz[node]+1, 0);
	cnt[0]=1;
	for (int v:G[root]) if (!dead[v]){
		dfs2(v, root, A[root], min(0, A[root]));
		dfs3(v, root, 0, 0);
	}
	if (A[root]==-1) ans+=cnt[1];
	reverse(all(G[root]));
	fill(cnt, cnt+sz[node]+1, 0);
	for (int v:G[root]) if (!dead[v]){
		dfs2(v, root, A[root], min(0, A[root]));
		dfs3(v, root, 0, 0);
	}
	
	for (int v:G[root]) if (!dead[v]) Decompose(v);
}


int main(){
	ios_base::sync_with_stdio(false);cin.tie(0);cout.tie(0);
	//freopen("input.txt", "r", stdin);
	//freopen("output.txt", "w", stdout);
	cin>>n;
	for (int i=1; i<=n; i++){
		char ch;
		cin>>ch;
		A[i]=(ch=='('?+1:-1);
	}
	for (int i=1; i<n; i++){
		cin>>u>>v;
		G[u].pb(v);
		G[v].pb(u);
	}
	
	Decompose(1);
	cout<<ans<<'\n';
	
	return 0;
}

• Subtask 1: 10 / 10
• Subtask 2: 30 / 30
• Subtask 3: 60 / 60