oj.uz

답안 #296148

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
296148 2020-09-10T10:45:51 Z eriksuenderhauf Power Plant (JOI20_power) C++17
0 / 100
 5 ms 4992 KB 
#include <bits/stdc++.h>
using namespace std;
const int N = 2e5 + 5;
vector<int> adj[N];
int dp[N], rsm[N], sm[N];

string s;

void dfs(int u, int p = -1) {
  dp[u] = -(s[u] == '1'); // don't cut
  sm[u] = 0;
  for (int v: adj[u]) if (v != p) {
    dfs(v, u);
    sm[u] += dp[v];
  }
  dp[u] = max(-dp[u], dp[u] + sm[u]);
}

void reroot(int u, int p = -1) {
  if (~p) {
    int vp = s[p] == '1' ? 1 : 0;
    rsm[u] = sm[u] + max(vp, -vp + rsm[p] - dp[u]);
  } else {
    rsm[u] = sm[u];
  }
  int vu = s[u] == '1' ? 1 : 0;
  dp[u] = max(vu, rsm[u] - vu);
  for (int v: adj[u]) if (v != p) {
    reroot(v, u);
  }
}

int main() {
  ios_base::sync_with_stdio(false); cin.tie(0);
  int n; cin >> n;
  for (int i = 1, u, v; i < n; i++) {
    cin >> u >> v; u--, v--;
    adj[u].push_back(v);
    adj[v].push_back(u);
  }
  cin >> s;
  int ans = 0;
  dfs(0);
  reroot(0);
  for (int i = 0; i < n; i++)
    ans = max(ans, dp[i]);
  cout << ans << "\n";
}

Subtask #1
0.0 / 6.0

# 결과 실행 시간 메모리 Grader output
1 Correct 4 ms 4992 KB Output is correct
2 Correct 4 ms 4992 KB Output is correct
3 Correct 4 ms 4992 KB Output is correct
4 Correct 4 ms 4992 KB Output is correct
5 Correct 5 ms 4992 KB Output is correct
6 Correct 4 ms 4992 KB Output is correct
7 Correct 4 ms 4992 KB Output is correct
8 Incorrect 4 ms 4992 KB Output isn't correct
9 Halted 0 ms 0 KB -

Subtask #2
0.0 / 41.0

# 결과 실행 시간 메모리 Grader output
1 Correct 4 ms 4992 KB Output is correct
2 Correct 4 ms 4992 KB Output is correct
3 Correct 4 ms 4992 KB Output is correct
4 Correct 4 ms 4992 KB Output is correct
5 Correct 5 ms 4992 KB Output is correct
6 Correct 4 ms 4992 KB Output is correct
7 Correct 4 ms 4992 KB Output is correct
8 Incorrect 4 ms 4992 KB Output isn't correct
9 Halted 0 ms 0 KB -

Subtask #3
0.0 / 53.0

# 결과 실행 시간 메모리 Grader output
1 Correct 4 ms 4992 KB Output is correct
2 Correct 4 ms 4992 KB Output is correct
3 Correct 4 ms 4992 KB Output is correct
4 Correct 4 ms 4992 KB Output is correct
5 Correct 5 ms 4992 KB Output is correct
6 Correct 4 ms 4992 KB Output is correct
7 Correct 4 ms 4992 KB Output is correct
8 Incorrect 4 ms 4992 KB Output isn't correct
9 Halted 0 ms 0 KB -