Submission #6055

#	Time	Username	Problem	Language	Result	Execution time	Memory
6055		kriii	오두막집 (GA7_cabana)	C++98	42 / 100	6000 ms	12020 KiB

cabana

#include <stdio.h>
#include <algorithm>
#include <vector>
using namespace std;

int N,M; long long K;
int x[100001],y[100001],c[100001],chk[100001]; bool fb[100001],ca[100001];
vector<int> g[100001];
int q[100001],z[100001],d[100001];

pair<vector<int>, long long> over(int s, int dist)
{
	int n = 0, h = 0;

	q[h] = s; d[h] = 0; h++; chk[s] = s;
	while (n < h){
		int u = q[n], w = d[n]; n++;

		for (int t=0,i;t<g[u].size();t++) if (!fb[i=g[u][t]]){
			int v = (u == x[i]) ? y[i] : x[i];
			if (chk[v] != s){
				q[h] = v; d[h] = (w+c[i]); h++; chk[v] = s;
			}
		}
	}

	int dif = 2*n; int st = q[0];
	for (int i=n-1;i>=0;i--){
		int u = q[i]; z[i] = 1;
		int mx = 0;
		for (int t=0,j;t<g[u].size();t++) if (!fb[j=g[u][t]]){
			int v = (u == x[j]) ? y[j] : x[j];
			if (chk[v] != s){
				z[i] += z[-chk[v]];
				mx = max(mx,z[-chk[v]]);
			}
		}
		mx = max(mx,n-z[i]);
		if (dif > mx) st = u, dif = mx;
		chk[u] = -i;
	}

	pair<vector<int>, long long> ret;
	for (int i=0;i<n;i++) if (ca[q[i]]) ret.first.push_back(d[i]);
	sort(ret.first.begin(),ret.first.end());
	ret.second = 0;

	vector<pair<vector<int>, long long> > a; vector<int> ad;
	for (int t=0,i;t<g[st].size();t++) if (!fb[i=g[st][t]]) fb[i] = 1, ad.push_back(i);
	for (int t=0;t<ad.size();t++) a.push_back(over(st==x[ad[t]]?y[ad[t]]:x[ad[t]],dist));
	for (int t=0;t<a.size();t++){
		int o = c[ad[t]];
		for (int r=0;r<a[t].first.size();r++){
			a[t].first[r] += o;
			if (ca[st] && a[t].first[r] <= dist) ret.second++;
		}
	}
	for (int t=0;t<ad.size();t++) fb[ad[t]] = 0;

	while (a.size() > 1){
		vector<pair<vector<int>, long long> > b;
		for (int k=0;k<a.size();k+=2){
			if (k + 1 == a.size()){b.push_back(a[k]); continue;}
			pair<vector<int>, long long> e;
			e.second = a[k].second + a[k+1].second;
			for (int i=0,j=(int)a[k+1].first.size()-1;i<a[k].first.size();i++){
				while (j >= 0 && a[k].first[i] + a[k+1].first[j] > dist) j--;
				e.second += j + 1;
			}
			int i=0,j=0;
			while (i<a[k].first.size() && j<a[k+1].first.size()){
				if (a[k].first[i] < a[k+1].first[j])
					e.first.push_back(a[k].first[i++]);
				else
					e.first.push_back(a[k+1].first[j++]);
			}
			while (i<a[k].first.size()) e.first.push_back(a[k].first[i++]);
			while (j<a[k+1].first.size()) e.first.push_back(a[k+1].first[j++]);
			b.push_back(e);
		}
		a.clear(); a = b; b.clear();
	}
	if (!a.empty()) ret.second += a[0].second;

	return ret;
}

int main()
{
	scanf ("%d %d %lld",&N,&M,&K);
	for (int i=2;i<=N;i++){
		scanf ("%d %d",&y[i],&c[i]); x[i] = i;
		g[x[i]].push_back(i);
		g[y[i]].push_back(i);
	}
	while (M--){
		int v; scanf ("%d",&v);
		ca[v] = 1;
	}

	int l = 1, r = 250 * N, m, a = -1;
	while (l <= r){
		m = (l + r) / 2;
		if (over(1,m).second >= K){
			r = m - 1;
			a = m;
		}
		else l = m + 1;
	}

	printf ("%d\n",a);

	return 0;
}

• Subtask 1: 7 / 7
• Subtask 2: 23 / 23
• Subtask 3: 12 / 12
• Subtask 4: 0 / 21
• Subtask 5: 0 / 37