제출 #76395

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
76395		MrTEK	Torrent (COI16_torrent)	C++14	0 / 100	171 ms	19836 KiB

torrent

#include <bits/stdc++.h>
using namespace std;
#define mp make_pair
#define pb push_back
#define len(a) (int)a.size()
#define fi first
#define sc second
#define d1(w) cerr<<#w<<":"<<w<<endl;
#define d2(w,c) cerr<<#w<<":"<<w<<" "<<#c<<":"<<c<<endl;
#define d3(w,c,z) cerr<<#w<<":"<<w<<" "<<#c<<":"<<c<<" "<<#z<<":"<<z<<endl;
#define left ind+ind
#define right ind+ind+1
#define mid (l+r)/2
#define FAST_IO ios_base::sync_with_stdio(false);
#define endl '\n'
#define bit __builtin_popcount

typedef long long int ll;

const int maxn = 620;
const long long LINF = 1e18;
const int LOG = 31;
const int INF = 1e9;
const int P = 31;
const int N = 3e5 + 5;
const int M = 1e6 + 5;
const int SQ = 350;
const int MOD = 1e9 + 7;

typedef long long int lli;
typedef pair<int,int> pii;

vector <int> ed[N];

int n,a,b,vis[N];

int solve(int cur,int back,int from) {
	int mx = -1,cnt = 0;
	for (auto i : ed[cur]) {
		if (i != back && vis[i] == from) {
			int temp = solve(i,cur,from);
			if (mx < temp) {
				mx = temp;
				cnt = 1;
			}
			else if (mx == temp) {
				cnt++;
			}
		}
	}
	if (mx == -1) return 0;
	return mx + cnt;
}

int main() {

	ios_base::sync_with_stdio(false);
	cin.tie(NULL); cout.tie(NULL);

	// freopen(".gir","r",stdin);
	// freopen(".cik","w",stdout);

	cin >> n >> a >> b;

	for (int i = 1 ; i < n ; i++) {
		int u,v;
		cin >> u >> v;
		ed[u].pb(v);
		ed[v].pb(u);
	}

	queue <pair <int,int> > Q;
	Q.push(mp(a,a));
	Q.push(mp(b,b));
	while(len(Q)) {
		auto temp = Q.front();
		Q.pop();
		if (vis[temp.fi]) continue;
		vis[temp.fi] = temp.sc;
		for (auto i : ed[temp.fi])
			Q.push(mp(i,temp.sc));
	}
	cout << max(solve(a,-1,a),solve(b,-1,b)) << endl;
}

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