Submission #6034

#	Time	Username	Problem	Language	Result	Execution time	Memory
6034		ainta	오두막집 (GA7_cabana)	C++98	0 / 100	364 ms	24880 KiB

cabana

#include<stdio.h>
#include<vector>
#include<algorithm>
using namespace std;
vector<int>E[100010], L[100010];
vector<int>P[100010];
struct Seg{
	int L, num;
	bool operator < (const Seg &p)const{
		return L < p.L;
	}
};
vector<Seg>w[100010];
int n, m, D[100010], L2[100010], Q[100010], par[100010], sz;
bool chk[100010], House[100010];
long long K;
void BFS(int a){
	int h = 0, t = 0, i, x;
	Q[++t] = a, D[a] = 1, L2[a] = 0;
	while (h < t){
		x = Q[++h];
		for (i = 0; i < E[x].size(); i++){
			if (!D[E[x][i]] && !chk[E[x][i]]){
				D[E[x][i]] = 1;
				Q[++t] = E[x][i];
				L2[E[x][i]] = L2[x] + L[x][i];
				par[E[x][i]] = x;
			}
		}
	}
	sz = t;
}
int GetMid(int a){
	int i, x;
	BFS(a);
	for (i = sz; i >= 1; i--){
		x = Q[i];
		D[par[x]] += D[x];
		if (D[x] >= sz / 2){
			break;
		}
	}
	for (i = 1; i <= sz; i++)D[Q[i]] = 0;
	return x;
}
void Do(int a)
{
	int Mid = GetMid(a);
	if (sz == 1){
		if (House[a])P[a].push_back(0);
		return;
	}
	int i, x, j;
	Seg tp;
	chk[Mid] = true;
	for (i = 0; i < E[Mid].size(); i++){
		x = E[Mid][i];
		if (!chk[x]){
			Do(x);
			for (j = 0; j < P[x].size(); j++){
				tp.L = P[x][j] + L[Mid][i];
				tp.num = x;
				w[Mid].push_back(tp);
			}
			P[x].resize(0);
		}
	}
	if (House[Mid]){
		tp.L = 0, tp.num = Mid;
		w[Mid].push_back(tp);
	}
	if (!w[Mid].empty()){
		sort(w[Mid].begin(), w[Mid].end());
	}
	chk[Mid] = false;
	BFS(a);
	for (i = 1; i <= sz; i++){
		D[Q[i]] = 0;
		if (House[Q[i]])P[a].push_back(L2[Q[i]]);
	}
}
int cnt[100010];
long long Gap(int Len)
{
	int i, pv, j, sz;
	long long S = 0;
	for (i = 1; i <= n; i++){
		if (w[i].empty())continue;
		pv = -1;
		sz = w[i].size();
		for (j = sz - 1; j >= 0; j--){
			while (pv + 1 < sz && w[i][pv + 1].L + w[i][j].L <= Len){
				pv++;
				cnt[w[i][pv].num]++;
			}
			S += pv + 1 - cnt[w[i][j].num];
		}
		for (j = 0; j <= pv; j++)cnt[w[i][j].num]--;
	}
	return S;
}
int main(){
	int i, a, b, be, ed, mid, Res;
	scanf("%d%d%lld", &n, &m, &K);
	for (i = 2; i <= n; i++){
		scanf("%d%d", &a, &b);
		E[a].push_back(i);
		E[i].push_back(a);
		L[a].push_back(b);
		L[i].push_back(b);
	}
	for (i = 0; i < m; i++){
		scanf("%d", &a);
		House[a] = true;
	}
	Do(1);
	be = 1, ed = 250 * (n - 1);
	while (be <= ed){
		mid = (be + ed) >> 1;
		if (Gap(mid) >= K * 2){
			Res = mid;
			ed = mid - 1;
		}
		else{
			be = mid + 1;
		}
	}
	printf("%d\n", Res);
}

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