oj.uz

Submission #76408

# Submission time Handle Problem Language Result Execution time Memory
76408 2018-09-13T12:57:08 Z MrTEK Torrent (COI16_torrent) C++14
0 / 100
 163 ms 20124 KB 
#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) {
	vector <int> v;
	for (auto i : ed[cur])
		if (i != back && vis[i] == from)
			v.pb(solve(i,cur,from));
	sort(v.begin(),v.end(),greater<int>());
	int re = 0,cnt = 0;
	for (auto i : v)	
		re = max(re,(++cnt) + i);
	return re;
}

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(b,b));
	Q.push(mp(a,a));
	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)) - 1 << endl;
}

Subtask #1
0 / 31.0

# Verdict Execution time Memory Grader output
1 Correct 8 ms 7416 KB Output is correct
2 Incorrect 8 ms 7548 KB Output isn't correct
3 Halted 0 ms 0 KB -

Subtask #2
0 / 69.0

# Verdict Execution time Memory Grader output
1 Incorrect 163 ms 20124 KB Output isn't correct
2 Halted 0 ms 0 KB -