oj.uz

답안 #761597

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
761597 2023-06-20T05:17:38 Z gun_gan Zagrade (COI17_zagrade) C++17
30 / 100
 181 ms 105792 KB 
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
 
const int MX = 3e5 + 5, inf = 1e9;
 
int N;
string s;
vector<int> g[MX];
 
int par[MX], bal[MX];
set<pair<int, int>> path[MX][2]; // open, close
// (balance, count)
 
int find(int v) {
      return par[v] == v ? v : par[v] = find(par[v]);
}
 
ll ans = 0;
 
void dfs(int v, int p) {
      for(auto u : g[v]) {
            if(u == p) continue;
            // build 
            bal[u] = bal[v] + (s[u] == '(' ? 1 : -1);
            dfs(u, v);
      }
 
      for(auto u : g[v]) {
            if(u == p) continue; 
 
            // erase invalid
            if(s[v] == ')') {
                  int pu = find(u);
                  auto it = path[pu][0].lower_bound({bal[v], -inf});
                  if(it != path[pu][0].end() && it->first == bal[v]) {
                        path[pu][0].erase(it);
                  }
            }
      
            if(s[v] == '(') {
                  int pu = find(u);

                  auto it = path[pu][1].lower_bound({bal[v], -inf});
                  if(it != path[pu][1].end() && it->first == bal[v]) {
                        path[pu][1].erase(it);
                  } 
            }
      }
 
      // straight path
      if(s[v] == ')') {
            for(auto u : g[v]) {
                  if(u == p) continue;
 
                  int pu = find(u);
                  auto it = path[pu][0].lower_bound({bal[p], -inf});
                  if(it != path[pu][0].end() && it->first == bal[p]) {
                        ans += it->second;
                  }
            }
      } else {
            for(auto u : g[v]) {
                  if(u == p) continue;
 
                  int pu = find(u);
                  auto it = path[pu][1].lower_bound({bal[p], -inf});
                  if(it != path[pu][1].end() && it->first == bal[p]) {
                        ans += it->second;
                  }
            }
      }
 
      // calc answer, merging
      for(auto u : g[v]) {
            if(u == p) continue;
            int pu = find(u), pv = find(v);
 
            // cout << u << " " << v << " " << pu << " " << pv << '\n';
 
            if((path[pu][0].size() + path[pu][1].size()) > (path[pv][0].size() + path[pv][1].size())) {
                  swap(pu, pv);
            }
 
            for(auto [b, c] : path[pu][0]) {
                  int k = b - bal[p];
                  k = -k + bal[v];
                  auto it = path[pv][1].lower_bound({k, -inf});
                  if(it != path[pv][1].end() && it->first == k) {
                        ans += 1LL * c * it->second;
                  }
            }
 
            for(auto [b, c] : path[pu][1]) {
                  int k = b - bal[p];
                  k = -k + bal[v];
                  auto it = path[pv][0].lower_bound({k, -inf});
                  if(it != path[pv][0].end() && it->first == k) {
                        ans += 1LL * c * it->second;
                  }
            }
 
            // cout << "merging " << u << " and "  << v << '\n';
 
            par[pu] = pv;
      }

      // cout << "cek isi \n";
      // for(auto [b, c] : path[find(v)][0]) cout << b << " " << c << '\n';
      // cout << '\n';
      // for(auto [b, c] : path[find(v)][1]) cout << b << " " << c << '\n';
      // cout << '\n';
 
      // add new path
      if(s[v] == '(') {
            int pv = find(v);
            auto it = path[pv][0].lower_bound({bal[v], -inf});

            if(it != path[pv][0].end() && it->first == bal[v]) {
                  path[pv][0].insert({it->first, it->second + 1});
                  path[pv][0].erase(*it);
            } else {
                  path[pv][0].insert({bal[v], 1});
            }
      } else {
            int pv = find(v);
            auto it = path[pv][1].lower_bound({bal[v], -inf});

            if(it != path[pv][1].end() && it->first == bal[v]) {
                  path[pv][1].insert({it->first, it->second + 1});
                  path[pv][1].erase(*it);
            } else {
                  path[pv][1].insert({bal[v], 1});
            }
      }

      // cout << v << " => " << ans << '\n';

      // cout << "cek isi \n";
      // for(auto [b, c] : path[find(v)][0]) cout << b << " " << c << '\n';
      // cout << '\n';
      // for(auto [b, c] : path[find(v)][1]) cout << b << " " << c << '\n';
      // cout << '\n';
}     
 
int main() {
      ios_base::sync_with_stdio(0); cin.tie(0);
 
      cin >> N >> s;
      s = '#' + s;
 
      for(int i = 0; i < N - 1; i++) {
            int u, v;
            cin >> u >> v;
            g[u].push_back(v);
            g[v].push_back(u);
      }
 
      for(int i = 1; i <= N; i++) par[i] = i;
 
      bal[1] = (s[1] == '(' ? 1 : -1);
      dfs(1, 0);
 
      // for(int i = 1; i <= N; i++) cout << bal[i] << " "; cout << '\n';
 
      cout << ans << '\n';
}

Subtask #1
0 / 10.0

# 결과 실행 시간 메모리 Grader output
1 Incorrect 16 ms 35540 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #2
30.0 / 30.0

# 결과 실행 시간 메모리 Grader output
1 Correct 140 ms 94564 KB Output is correct
2 Correct 152 ms 104280 KB Output is correct
3 Correct 139 ms 98776 KB Output is correct
4 Correct 146 ms 102948 KB Output is correct
5 Correct 140 ms 98728 KB Output is correct
6 Correct 150 ms 100616 KB Output is correct
7 Correct 140 ms 98660 KB Output is correct
8 Correct 144 ms 100648 KB Output is correct
9 Correct 139 ms 98724 KB Output is correct
10 Correct 181 ms 105792 KB Output is correct
11 Correct 119 ms 98616 KB Output is correct

Subtask #3
0 / 60.0

# 결과 실행 시간 메모리 Grader output
1 Incorrect 16 ms 35540 KB Output isn't correct
2 Halted 0 ms 0 KB -