Submission #571672

#	Time	Username	Problem	Language	Result	Execution time	Memory
571672		BackNoob	Mousetrap (CEOI17_mousetrap)	C++14	0 / 100	744 ms	73292 KiB

mousetrap

#include <bits/stdc++.h>
#define ll long long
#define fi first
#define se second
#define endl '\n'
#define MASK(i) (1LL << (i))
#define ull unsigned long long
#define ld long double
#define pb push_back
#define all(x) (x).begin() , (x).end()
#define BIT(x , i) ((x >> (i)) & 1) 
#define TASK "task"
#define sz(s) (int) (s).size()

using namespace std;
const int mxN = 1e6 + 227;
const int inf = 1e9 + 277;
const int mod = 1e9 + 7;
const ll infll = 1e18 + 7;
const int base = 200;
const int LOG = 20;
 
template <typename T1, typename T2> bool minimize(T1 &a, T2 b) {
	if (a > b) {a = b; return true;} return false;
}
template <typename T1, typename T2> bool maximize(T1 &a, T2 b) {
	if (a < b) {a = b; return true;} return false;
}

int n;
int t;
int m;
int dp[mxN];
vector<int> adj[mxN];

void dfs(int u, int par)
{
	vector<int> val;
	for(int v : adj[u]) {
		if(v == par || v == t) continue;
		dfs(v, u);
		val.pb(dp[v]);
	}

	sort(all(val));
	reverse(all(val));

	if(sz(val) <= 1) dp[u] = 0;
	else dp[u] = val[1] + 1;
}

void solve()
{	
	cin >> n >> t >> m;
	for(int i = 1; i < n; i++) {
		int u, v;
		cin >> u >> v;
		adj[u].pb(v);
		adj[v].pb(u);
	}

	dfs(m, -1);
	cout << dp[m] * 2 << endl;
}
 
int main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    //freopen(TASK".in" , "r" , stdin);
    //freopen(TASK".out" , "w" , stdout);
	

    int tc = 1;
    // cin >> tc;
    while(tc--) {
    	solve();
    }
    return 0;
}

• Subtask 1: 0 / 20
• Subtask 2: 0 / 25
• Subtask 3: 0 / 20
• Subtask 4: 0 / 35