Submission #411278

#	Time	Username	Problem	Language	Result	Execution time	Memory
411278		nichke	Power Plant (JOI20_power)	C++14	100 / 100	211 ms	31272 KiB

power

#include <bits/stdc++.h>
using namespace std;
#define int long long
#define endl '\n'

int n;
int cnt;
string s;

vector<int> adj[200005];
bool pw[200005];
int dp[200005][2];

void dfs(int v, int p = -1) {
	if (s[v] == '1') dp[v][0] = 1;
	int tot = 0, mx = 0;
	for (int u : adj[v]) {
		if (u == p) continue;
		dfs(u, v);
		tot += dp[u][0];
		mx = max(mx, dp[u][0]);
	}
	dp[v][0] = max(tot - dp[v][0], dp[v][0]);
	if (s[v] == '1') dp[v][1] = mx + 1;
}

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

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