Submission #896802

#	Time	Username	Problem	Language	Result	Execution time	Memory
896802		dwuy	Zagrade (COI17_zagrade)	C++14	100 / 100	552 ms	74760 KiB

zagrade

/// dwuy: _,\,,,_\,__,\,,_
#include <bits/stdc++.h>

#define fastIO ios_base::sync_with_stdio(false); cin.tie(NULL)
#define file(a) freopen(a".inp","r",stdin); freopen(a".out", "w",stdout)
#define fi first
#define se second
#define endl "\n"
#define len(s) int32_t(s.length())
#define MASK(k)(1LL<<(k))
#define TASK ""
#define int long long

using namespace std;

typedef tuple<int, int, int> tpiii;
typedef pair<double, double> pdd;
typedef pair<int, int> pii;
typedef long long ll;

const long long OO = 1e18;
const int MOD = 1e9 + 7;
const int INF = 1e9;
const int MX = 300005;

int n;
string a;
vector<int> G[MX];

void nhap(){
    cin >> n;
    cin >> a; a = ' ' + a;
    for(int i=1; i<n; i++){
        int u, v;
        cin >> u >> v;
        G[u].push_back(v);
        G[v].push_back(u);
    }
}

int numC[MX];
bitset<MX> vist = 0;

void calChild(int u){
    vist[u] = 1;
    numC[u] = 1;
    for(int v: G[u]) if(!vist[v]){
        calChild(v);
        numC[u] += numC[v];
    }
    vist[u] = 0;
}

int centroid(int u, int p, const int &half){
    for(int v: G[u]) if(v!=p && !vist[v]){
        if(numC[v] > half) return centroid(v, u, half);
    }
    return u;
}

int p[MX];
int op[MX];
int cl[MX];
int fop[MX];
int fcl[MX];

int c1(char c){
    return c==')'? 1 : -1;
}

int c2(char c){
    return -c1(c);
}

int getmap(int val, const map<int, int> &mp){
    auto itr = mp.find(val);
    return itr == mp.end()? 0 : itr->se;
}

int calc(int u){
    int res = 0;
    map<int, int> mp1, mp2;
    if(c1(a[u]) < 0) mp1[-1]++;
    for(int v: G[u]) if(!vist[v]){
        vector<int> node1, node2;
        stack<int> Q;
        Q.push(v);
        p[v] = u;
        op[v] = c1(a[u]) + c1(a[v]);
        cl[v] = c2(a[v]);
        fop[v] = min({0LL, c1(a[u]), op[v]});
        fcl[v] = min(0LL, c2(a[v]));
        while(Q.size()){
            int u = Q.top();
            Q.pop();
            if(cl[u] == fcl[u]){
                res += getmap(cl[u], mp1);
                node2.push_back(u);
            }
            if(op[u] == fop[u]){
                res += getmap(op[u], mp2);
                node1.push_back(u);
            }
            for(int v: G[u]) if(!vist[v] && v!=p[u]){
                Q.push(v);
                p[v] = u;
                op[v] = op[u] + c1(a[v]);
                cl[v] = cl[u] + c2(a[v]);
                fop[v] = min(fop[u], op[v]);
                fcl[v] = min(fcl[u], cl[v]);
            }
        }
        for(int u: node1) mp1[op[u]]++, res += op[u]==0;
        for(int u: node2) mp2[cl[u]]++;
    }
    return res;
}

int solve(int u){
    calChild(u);
    u = centroid(u, 0, numC[u]>>1);
    int res = calc(u);
    vist[u] = 1;
    for(int v: G[u]) if(!vist[v]) res += solve(v);
    return res;
}

int32_t main(){
    fastIO;
    //file(TASK);

    nhap();
    cout << solve(1);

    return 0;
}

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