Submission #1231764

#	Time	Username	Problem	Language	Result	Execution time	Memory
1231764		PlayVoltz	Evacuation plan (IZhO18_plan)	C++20	100 / 100	560 ms	81964 KiB

plan

#include <cstdio>
#include <stdio.h>
#include <stdbool.h>
#include <iostream>
#include <map>
#include <vector>
#include <climits>
#include <stack>
#include <string>
#include <queue>
#include <algorithm>
#include <set>
#include <unordered_set>
#include <unordered_map>
#include <cmath>
#include <cctype>
#include <bitset>
#include <iomanip>
#include <cstring>
#include <numeric>
#include <cassert>
#include <random>
#include <chrono>
#include <fstream>
using namespace std;

#define int long long
#define pii pair<int, int>
#define mp make_pair
#define pb push_back
#define fi first
#define se second

vector<int> dsu, depth, dj;
vector<vector<int> > twok, mn;
vector<vector<pii> > graph;

int fp(int a){
	if (dsu[a]==-1)return a;
	return dsu[a]=fp(dsu[a]);
}

bool merge(int a, int b){
	a=fp(a), b=fp(b);
	if (a==b)return 0;
	dsu[a]=b;
	return 1;
}

void dfs(int node, int par, int d){
	depth[node]=d;
	twok[node][0]=par;
	mn[node][0]=dj[par];
	for (int i=1; i<20; ++i)twok[node][i]=twok[twok[node][i-1]][i-1], mn[node][i]=min(mn[node][i-1], mn[twok[node][i-1]][i-1]);
	for (auto num:graph[node])if (num.fi!=par)dfs(num.fi, node, d+1);
}

int lca(int a, int b){
	if (depth[a]<depth[b])swap(a, b);
	int res=min(dj[a], dj[b]);
	for (int i=0, k=depth[a]-depth[b]; i<20; ++i)if (k&(1<<i))res=min(res, mn[a][i]), a=twok[a][i];
	if (a==b)return res;
	for (int i=19; i>=0; --i)if (twok[a][i]!=twok[b][i])res=min({res, mn[a][i], mn[b][i]}), a=twok[a][i], b=twok[b][i];
	return min(res, dj[twok[a][0]]);
}

int32_t main(){
	ios_base::sync_with_stdio(0);
	cin.tie(0);
	cout.tie(0);
	int n, m, k, q, a, b, c;
	cin>>n>>m;
	graph.resize(n+1);
	vector<pii> temp;
	while (m--){
		cin>>a>>b>>c;
		temp.pb(mp(a, b));
		graph[a].pb(mp(b, c));
		graph[b].pb(mp(a, c));
	}
	dj.resize(n+1, LLONG_MAX/2);
	priority_queue<pii, vector<pii>, greater<pii> > pq;
	cin>>k;
	while (k--)cin>>a, pq.push(mp(0, a));
	while (pq.size()){
		int d=pq.top().fi, node=pq.top().se;
		pq.pop();
		if (d>=dj[node])continue;
		dj[node]=d;
		for (auto num:graph[node])pq.push(mp(dj[node]+num.se, num.fi));
	}
	vector<pair<int, pii> > edges;
	for (auto a:temp)edges.pb(mp(min(dj[a.fi], dj[a.se]), mp(a.fi, a.se)));
	sort(edges.begin(), edges.end(), greater<pair<int, pii> >());
	dsu.resize(n+1, -1);
	graph.clear();
	graph.resize(n+1);
	for (auto c:edges)if (merge(c.se.fi, c.se.se)){
		graph[c.se.fi].pb(mp(c.se.se, c.fi));
		graph[c.se.se].pb(mp(c.se.fi, c.fi));
	}
	depth.resize(n+1);
	twok.resize(n+1, vector<int>(20));
	mn.resize(n+1, vector<int>(20, LLONG_MAX/2));
	dfs(1, 1, 0);
	cin>>q;
	while (q--){
		cin>>a>>b;
		cout<<lca(a, b)<<"\n";
	}
}

• Subtask 1: 10 / 10
• Subtask 2: 13 / 13
• Subtask 3: 12 / 12
• Subtask 4: 19 / 19
• Subtask 5: 46 / 46