Submission #79096

#	Time	Username	Problem	Language	Result	Execution time	Memory
79096		gs14004	Factories (JOI14_factories)	C++17	0 / 100	36 ms	12408 KiB

factories

#include "factories.h"
#include <vector>
#include <queue>
#include <utility>
#include <algorithm>
using namespace std;
typedef long long lint;
typedef pair<lint,int> pi;

vector<pi> graph[500005];

int piv, dfn[500005];
int dep[500005], sz[500005];
lint dist[500005];
int par[500005][19];

int dfs(int x, int p){
	dfn[x] = ++piv;
	sz[x] = 1;
	for (auto &i : graph[x]){
		if(p == i.second) continue;
		dep[i.second] = dep[x] + 1;
		dist[i.second] = dist[x] + i.first;
		par[i.second][0] = x;
		sz[x] += dfs(i.second, x);
	}
	return sz[x];
}

void Init(int N, int A[], int B[], int D[]){
	for (int i=0; i<N-1; i++) {
		graph[A[i]+1].push_back(pi(D[i],B[i]+1));
		graph[B[i]+1].push_back(pi(D[i],A[i]+1));
	}
	dfs(1, 0);
	for(int i=1; i<=18; i++){
		for(int j=1; j<=N; j++){
			par[j][i] = par[par[j][i-1]][i-1];
		}
	}
}

int lca(int x, int y){
	if(dep[x] < dep[y]) swap(x,y);
	int dx = dep[x] - dep[y];
	for(int i=0; (1<<i)<=dx; i++){
		if((dx >> i) & 1) x = par[i][x];
	}
	for (int i=18; i>=0; i--) {
		if(par[i][x] != par[i][y]){
			x = par[x][i];
			y = par[y][i];
		}
	}
	if(x != y) x = par[x][0];
	return x;
}

bool cmp(int a, int b){
	return dfn[a] < dfn[b];
}

bool sub(int a, int b){
	return dfn[a] + sz[a] >= dfn[b] + sz[b];
}

vector<int> pos;
int c;
int object[500005];
lint D[500005];

void const_g(){
	vector<int> stk;
	for(auto &i : pos){
		if(stk.empty()) stk.push_back(i);
		else{
			while(!stk.empty() && !sub(stk.back(), i)) stk.pop_back();
			int par = stk.back();
			int cur = i;
			graph[par].emplace_back(dist[cur] - dist[par], cur);
			graph[cur].emplace_back(dist[cur] - dist[par], par);
			stk.push_back(cur);
		}
	}
}

lint dijkstra(int n, int* s){
	priority_queue<pi,vector<pi>,greater<pi> > pq;
	for (int i=0; i<n; i++) {
		pq.push(pi(0ll,s[i] + 1));
		D[s[i] + 1] = 0;
	}
	while (!pq.empty()) {
		pi t = pq.top();
		pq.pop();
		if(D[t.second] != t.first) continue;
		if(object[t.second] == c) return t.first;
		for(auto &i : graph[t.second]){
			if(D[i.second] > t.first + i.first){
				D[i.second] = t.first + i.first;
				pq.push(pi(D[i.second], i.second));
			}
		}
	}
	return -1;
}

lint Query(int S, int X[], int T, int Y[]){
	c++;
	pos.clear();
	for (int i=0; i<S; i++) {
		pos.push_back(X[i]+1);
	}
	for (int i=0; i<T; i++) {
		object[Y[i]+1] = c;
		pos.push_back(Y[i]+1);
	}
	sort(pos.begin(),pos.end(),cmp);
	int p = (int)pos.size() - 1;
	for (int i=0; i<p; i++) {
		pos.push_back(lca(pos[i],pos[i+1]));
	}
	sort(pos.begin(),pos.end(),cmp);
	pos.resize(unique(pos.begin(),pos.end()) - pos.begin());
	for(auto &i : pos){
		D[i] = 1e18;
		graph[i].clear();
	}
	const_g();
	lint ret = dijkstra(S,X);
	return ret;
}

• Subtask 1: 0 / 15
• Subtask 2: 0 / 18
• Subtask 3: 0 / 67