Submission #1036220

#	Time	Username	Problem	Language	Result	Execution time	Memory
1036220		sinatbtfard	Railway (BOI17_railway)	C++17	0 / 100	1020 ms	23376 KiB

railway

#include <bits/stdc++.h>

#define pb push_back

using namespace std;

const int maxn = 1e5 + 1, maxLg = 20;

int n, q, k, timer, cnt, a[maxn], h[maxn], st[maxn], fn[maxn], par[maxn][maxLg];
vector <int> adj[maxn], res;

void dfs (int v, int p = 0){
	st[v] = timer++;
	par[v][0] = p;
	for (int i = 1; i < maxLg; i++)
		par[v][i] = par[par[v][i - 1]][i - 1];
	for (auto u : adj[v]){
		if (u != p){
			h[u] = h[v] + 1;
			dfs(u, v);
		}
	}
	fn[v] = timer++;
}

int lca (int v, int mnst, int mxfn){
	for (int i = maxLg - 1; i >= 0; i--){
		if (par[v][i] == 0)
			continue;
		int u = par[v][i];
		if (!(st[u] <= mnst && fn[u] >= mxfn))
			v = u;
	}
	return par[v][0];
}

void dfs2 (int v, int p = 0){
	for (auto u : adj[v])
		if (u != p)
			dfs2(u, v);
	if (adj[v].size() == 1 && v != 1)
	    cnt = 0;
	if ((cnt += a[v]) >= k)
		res.pb(v);
}

int main (){
	ios_base::sync_with_stdio(0);
	cin >> n >> q >> k;
	for (int x, y, i = 0; i < n - 1; i++)
		cin >> x >> y,
		adj[x].pb(y),
		adj[y].pb(x);
	dfs(1);
	int tmp = 1, mnst = 1e8, mxfn = -1;
	for (int s, i = 0; i < q; i++){
		cin >> s;
		for (int x, i = 0; i < n; i++)
			cin >> x,
			a[x]++,
			tmp = (h[tmp] < h[x] ? x : tmp),
			mnst = min(mnst, st[x]),
			mxfn = max(mxfn, fn[x]);
		a[lca(tmp, mnst, mxfn)] -= s;
	}
	dfs2(1);
	cout << res.size() << '\n';
	for (auto ver : res)
		cout << ver << " ";
}

• Subtask 1: 0 / 8
• Subtask 2: 0 / 15
• Subtask 3: 0 / 7
• Subtask 4: 0 / 29
• Subtask 5: 0 / 16
• Subtask 6: 0 / 25