Submission #698573

#	Time	Username	Problem	Language	Result	Execution time	Memory
698573		jcelin	Zagrade (COI17_zagrade)	C++14	100 / 100	1389 ms	76840 KiB

zagrade

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

using namespace std;
//using namespace __gnu_pbds;

typedef long long ll;
typedef long double ld;

#define ii pair<int,int>
#define pll pair<ll,ll>
#define vi vector<int>
#define vii vector<ii>
#define vll vector<ll>
#define vpll vector<pll>
#define msi multiset<int>
#define si set<int>
#define PB push_back
#define PF push_front
#define PPB pop_back
#define PPF pop_front
#define X first
#define Y second
#define MP make_pair
#define FOR(i, a, b) for (int i = int(a); i < int(b); i++)
#define REP(i, n) FOR(i, 0, n)
#define all(x) (x).begin(), (x).end()

const int dx[] = {-1, 1, 0, 0};
const int dy[] = {0, 0, -1, 1};
const int dxx[] = {-1, 1, 0, 0, 1, 1, -1, -1};
const int dyy[] = {0, 0, -1, 1, -1, 1, -1, 1};
const int mod = 1e9 + 7;
const int MOD = 1e9 + 7;
const int MAXN = 1e6 + 7;
const int inf = mod;
const ll INF = 1e18;
const int logo = 20;
const int off = 1 << logo;
const int trsz = off << 1;

string s;
int n, sz[MAXN];
bool bio[MAXN];
ll ans = 0;
vi g[MAXN];
map<ii, int> f;

void dfs(int u, int p = -1){
	sz[u] = 1;
	for(auto &x : g[u]) if(x != p and !bio[x]) dfs(x, u), sz[u] += sz[x];
}

int cen(int u, int p, int szi){
	for(auto &x : g[u]) if(x != p and !bio[x]) if(sz[x] * 2 > szi) return cen(x, u, szi);
	return u; 
}

void dodaj(int x, int t, int a = 0, int b = 0, int p = -1){
	if(s[x] == '(') a++;
	else{
		if(a) a--;
		else b++;
	}
	
	f[{a, b}] += t;
	
	for(auto &y : g[x]) if(!bio[y] and y != p) dodaj(y, t, a, b, x);
}

void rijesi(int x, int centr, int a = 0, int b = 0, int p = -1){
	if(s[x] == ')') b++;
	else{
		if(b) b--;
		else a++;
	}
	
	int na = a, nb = b;
	if(s[centr] == '(') na++;
	else{
		if(na) na--;
		else nb++;
	}
	
	if(nb == 0) ans += (ll)f[{0, na}];
	for(auto &y : g[x]) if(!bio[y] and y != p) rijesi(y, centr, a, b, x);
}

void decompose(int u){
	dfs(u);
	int centr = cen(u, -1, sz[u]);
	//sad napravi rjesenje
	
	bio[centr] = 1;
	f.clear(); f[{0, 0}] = 1;
	for(auto &x : g[centr]) if(!bio[x]) dodaj(x, 1);
	
	if(s[centr] == '(') ans += (ll)f[{0, 1}];

	for(auto &x : g[centr]){
		if(bio[x]) continue;
		dodaj(x, -1);
		rijesi(x, centr);
		dodaj(x, 1);
	}
	
	for(auto &x : g[centr]) if(!bio[x]) decompose(x);
}

void solve(){
	cin >> n >> s;
	REP(i, n - 1){
		int a, b;
		cin >> a >> b;
		a--, b--;
		g[a].PB(b);
		g[b].PB(a);
	}
	dfs(0);
	decompose(0);
	cout << ans << "\n";
}


int main(){
	ios_base::sync_with_stdio(false);
	cin.tie(NULL);
	cout.tie(NULL);
	int t=1;
	//cin >> t;
	while(t--)solve();
	return 0;
}

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