Submission #914050

#	Time	Username	Problem	Language	Result	Execution time	Memory
914050		OAleksa	Power Plant (JOI20_power)	C++14	0 / 100	2 ms	8796 KiB

power

#include <bits/stdc++.h>
//ako ovaj vaso daso misli da me pobedjuje.....
using namespace std;
#define int long long
#define f first
#define s second
const int N = 2e5 + 69;
int n, mark[N], dp[N], up[N];
vector<int> g[N];
string s;
void dfs(int v, int p) {
	int x = 0;
	for (auto u : g[v]) {
		if (u == p)
			continue;
		dfs(u, v);
		x += (dp[u] > 0);
	}
	sort(g[v].begin(), g[v].end(), [&](int i, int j) {
		return dp[i] > dp[j];
	});
	if (mark[v]) {
		if (x < 2) {
			dp[v] = 1;
			for (auto u : g[v]) {
				if (u == p)
					continue;
				dp[v] = dp[u];
				if (dp[u] > 2) {
					if (up[u] == 0) 
						dp[v]++;
					up[v] = 1;
				}
			}
		}
		else {
			for (auto u : g[v]) {
				if (u == p)
					continue;
				dp[v] += dp[u] - 2 * up[u];
			}
			dp[v]--;
			if (dp[v] <= 2 && up[v]) {
				dp[v] = 1;
				up[v] = 0;
			}
		}
	}
	else {
		int mx = 0;
		for (auto u : g[v]) {
			if (u == p)
				continue;
			dp[v] += dp[u] - 2 * up[u];
			mx = max(mx, dp[u]);
		}
		dp[v] = max(dp[v], mx);
	}
}
signed main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  int tt = 1;
  //cin >> tt;
  while (tt--) {
  	cin >> n;
  	for (int i = 1;i <= n - 1;i++) {
			int a, b;
			cin >> a >> b;
			g[a].push_back(b);
			g[b].push_back(a);
  	}
  	cin >> s;
  	for (int i = 0;i < n;i++) {
  		if (s[i] == '1')
  			mark[i + 1] = 1;
  	}
  	dfs(1, 0);
  	int t = 1, p = 0;
  	while (g[t].size() <= 2 && t != -1) {
  		if (dp[t] == dp[1] && mark[t]) {
  			dp[1]++;
  			break;
  		}
  		int x = t;
  		t = -1;
  		for (auto u : g[x]) {
  			if (u == p)
  				continue;
  			p = t;
  			t = u;
  		}
  	}
  	cout << dp[1] << endl;
	}
  return 0;
}

• Subtask 1: 0 / 6
• Subtask 2: 0 / 41
• Subtask 3: 0 / 53