Submission #1197754

#	Time	Username	Problem	Language	Result	Execution time	Memory
1197754		aykhn	Power Plant (JOI20_power)	C++20	100 / 100	81 ms	48780 KiB

power

#include <bits/stdc++.h>

using namespace std;

#define int long long
#define inf 0x3F3F3F3F3F3F3F3F

const int MXN = 1e6 + 5;
const int mod = 1e9 + 7;

int n;
vector<int> adj[MXN];
int dp[MXN], val[MXN], sum[MXN];
int res = 0;

void dfs(int a, int p)
{
  sum[a] = val[a];
  for (int &v : adj[a])
  {
    if (v == p) continue;
    dfs(v, a);
    sum[a] += sum[v];
    dp[a] += dp[v];
  }
  dp[a] = max(dp[a], sum[a] + val[a]);
  res = max(res, dp[a] - sum[a]);
  if (!val[a]) return;
  for (int &v : adj[a])
  {
    if (v == p) continue;
    res = max(res, dp[v] - sum[v] + 1);
  }
}

void _()
{
  cin >> n;
  for (int i = 1; i < n; i++)
  {
    int u, v;
    cin >> u >> v;
    adj[u].push_back(v);
    adj[v].push_back(u);
  }
  for (int i = 1; i <= n; i++)
  {
    char ch;
    cin >> ch;
    val[i] = ch - '0';
  }
  dfs(1, 1);
  cout << res << '\n';
}

signed main()
{
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  int t = 1;
  // cin >> t;
  while (t--) _();
}

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