Submission #478386

#	Time	Username	Problem	Language	Result	Execution time	Memory
478386		jesus_coconut	Power Plant (JOI20_power)	C++17	100 / 100	210 ms	28064 KiB

power

#include <bits/stdc++.h>
#define F first
#define S second
#define all(a) begin(a), end(a)


using namespace std;

int const N = 200005;

int n;
vector<int> adj[N];
string s;

void input() {
  cin >> n;
  for (int i = 0; i < n - 1; ++i) {
    int a, b;
    cin >> a >> b;
    --a; --b;
    adj[a].push_back(b);
    adj[b].push_back(a);
  }
  cin >> s;
}

int ans = 0;

int dp(int ver, int par) {
  int ret = s[ver] == '1';
  int suma = 0;
  for (auto u : adj[ver]) if (u != par) {
    int a = dp(u, ver);
    if (a > 0) suma += a;
    if (s[ver] == '1') {
      ans = max(ans, a + 1);
    }
  }
  ret = max(ret, suma - (s[ver] == '1'));
  ans = max(ans, ret);
  return ret;
}

void solve() {
  dp(0, -1);
  cout << ans << '\n';
}

int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(nullptr);

  input();
  solve();

  return 0;
}

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