Submission #211386

#	Time	Username	Problem	Language	Result	Execution time	Memory
211386		Fischer	Torrent (COI16_torrent)	C++14	0 / 100	306 ms	23032 KiB

torrent

#include <bits/stdc++.h>
using namespace std;
const int maxn = 3e5 + 10;
bool vis[maxn];
vector<int> g[maxn];
int n, a, b;
int dp[maxn];

int dfs(int x) {
	vis[x] = 1;
	vector<int> t;
	for (int v : g[x]) {
		if (vis[v]) continue;
		dfs(v);
		t.push_back(dp[v]);
	}
	sort(t.rbegin(), t.rend());
	int ans = 0;
	for (int i = 0; i < t.size(); ++i) {
		ans = max(ans, t[i] + i + 1);
	}
	dp[x] = ans;
}

int main() {
	cin >> n >> a >> b;
	for (int i = 1; i <= n-1; ++i) {
		int x, y;
		cin >> x >> y;
		g[x].push_back(y);
	}
	vis[a] = vis[b] = 1;
	dfs(a); dfs(b);
	cout << max(dp[a], dp[b]) << endl;
	return 0;
}

Compilation message (stderr)

torrent.cpp: In function 'int dfs(int)':
torrent.cpp:19:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for (int i = 0; i < t.size(); ++i) {
                  ~~^~~~~~~~~~
torrent.cpp:23:1: warning: no return statement in function returning non-void [-Wreturn-type]
 }
 ^

• Subtask 1: 0 / 31
• Subtask 2: 0 / 69