Submission #82510

#	Time	Username	Problem	Language	Result	Execution time	Memory
82510		Good	Evacuation plan (IZhO18_plan)	C++11	19 / 100	3411 ms	20792 KiB

plan

#include <algorithm>
#include <iostream>
#include <string.h>
#include <stdio.h>
#include <vector>
#include <queue>
#include <cmath>
#include <set>
#include <map>

#define N 100010
#define ff first
#define ss second
#define pb push_back
#define ll long long
#define pii pair <int, int>

using namespace std;

int k;
int n, m, q;
int a, b, c;

int ans[N];
int Par[N];
int L[N], R[N];
int v[N], vis[N];
pii p[N * 5], P[N * 5];
vector <pii> E[N];
priority_queue <pii, vector <pii>, greater <pii>> Q;

int ata(int x)
{
	if (x == Par[x]) return x;
	
	return Par[x] = ata(Par[x]);
}

void uni(int x, int y) {
	x = ata(x);
	y = ata(y);
	
	if (x == y) return;
	
	Par[y] = x;
}

int main()
{
	cin >> n >> m;
	
	for(int i = 1; i <= n; i++)
		L[i] = 0, R[i] = 1e9, v[i] = 1e9;
	
	for(int i = 1; i <= m; i++) {
		cin >> a >> b >> c;
		
		E[a].pb({b, c});
		E[b].pb({a, c});
	}
	
	cin >> k;
	
	for(int i = 1; i <= k; i++) {
		cin >> a;
		Q.push({0, a}), v[a] = 0;
	}
	
	while(!Q.empty()) {
		pii p = Q.top();
		Q.pop();
		
		if(vis[p.ss] == 1) continue;
		vis[p.ss] = 1;
		
		for(auto i: E[p.ss])
			if (i.ss + p.ff < v[i.ff])
				v[i.ff] = i.ss + p.ff, Q.push({v[i.ff], i.ff});
	}
	
	for(int i = 1; i <= n; i++) P[i] = {v[i], i};
	
	sort(P+1, P+n+1);
	
	cin >> q;
	
	for(int i = 1; i <= q; i++)
		cin >> p[i].ff >> p[i].ss;
	
	P[0] = {-1, -1};
	while (1) {
		set <pii> M;
		
		for(int i = 1; i <= n; i++) Par[i] = i;
		
		for(int i = 1; i <= q; i++)
			if (L[i] <= R[i])
				M.insert({(L[i] + R[i])/2, i});
		
		if (!M.size())
			break;
		
		memset(vis, 0, sizeof (vis));
		
		for(int i = n; i >= 1; i--)
		{
			int nd = P[i].ss;
			
			vis[nd] = 1;
			for(auto h: E[nd])
				if (vis[h.ff] == 1) uni(nd, h.ff);
			
			if (!M.empty()) {
				pii last = *M.rbegin();
				
				while(!M.empty() && last.ff > P[i-1].ff) {
					a = p[last.ss].ff;
					b = p[last.ss].ss;
					
					if (ata(a) == ata(b)) ans[last.ss] = last.ff, L[last.ss] = last.ff + 1;
					else R[last.ss] = last.ff - 1;
					
					M.erase(last);
					
					if(!M.empty()) last = *M.rbegin();
				}
			}
		}
	}
	
	for(int i = 1; i <= q; i++) cout << ans[i] << '\n';
}
/*
10 13
1 10 20
4 9 14
5 6 10
9 7 10
7 8 8
7 6 7
4 5 5
10 9 5
10 3 3
3 4 3
10 7 3
2 3 2
1 2 1
2
9 8
2
3 6
4 7
*/

• Subtask 1: 0 / 10
• Subtask 2: 0 / 13
• Subtask 3: 0 / 12
• Subtask 4: 19 / 19
• Subtask 5: 0 / 46