Submission #913533

#	Time	Username	Problem	Language	Result	Execution time	Memory
913533		pan	Airplane (NOI23_airplane)	C++17	100 / 100	814 ms	40304 KiB

Main

#include <bits/stdc++.h>
//#include "bits_stdc++.h"
#define f first
#define s second
#define mp make_pair
#define pb push_back
#define lb lower_bound
#define ub upper_bound
//#define input(x) scanf("%lld", &x);
//#define print(x, y) printf("%lld%c", x, y);
#define show(x) cerr << #x << " is " << x << endl;
#define show2(x,y) cerr << #x << " is " << x << " " << #y << " is " << y << endl;
#define show3(x,y,z) cerr << #x << " is " << x << " " << #y << " is " << y << " " << #z << " is " << z << endl;
using namespace std;
typedef long long ll;
typedef long double ld;
typedef pair<ld, ll> pd;
typedef pair<string, ll> psl;
typedef pair<ll, ll> pi;
typedef pair<ll, pi> pii;
ll n, m;
vector<ll> height;
vector<ll> adj[200005];
pi edges[400005];
ll const INF = LLONG_MAX/3;
vector<ll> dijkstra(ll from)
{
	vector<ll> visited(n+1, false);
	vector<ll> dist(n+1, INF);
	dist[from] = 0;
	priority_queue<pi, vector<pi>, greater<pi> > pq;
	pq.push(mp(0, from));
	while (pq.size())
	{
		ll c = pq.top().s;
		pq.pop();
		if (visited[c]) continue;
		visited[c] = true;
		for (ll u: adj[c])
		{
			ll neww = max(dist[c]+1, height[u]);
			if (dist[u]>neww)
			{
				dist[u] = neww;
				pq.push(mp(neww, u));
			}
		}
	}
	return dist;
}
int main()
{
	cin >> n >> m;
	height.resize(n+1);
	for (ll i=1; i<=n; ++i) cin >> height[i];
	for (ll i=0; i<m; ++i)
	{
		ll x, y;
		cin >> x >> y;
		edges[i].f = x, edges[i].s = y;
		adj[x].pb(y);
		adj[y].pb(x);
	}
	vector<ll> up, down;
	up = dijkstra(1); down = dijkstra(n);
	ll ans = LLONG_MAX;
	// if maintain for 0 sec
	for (ll i=2; i<n; ++i)
	{
		ans = min(ans, max(up[i], down[i])*2);
	}
	// if maintain for 1 sec
	for (ll i=0; i<m; ++i)
	{
		pi x = edges[i];
		ans = min(ans, max(up[x.f], down[x.s])*2+1);
		ans = min(ans, max(up[x.s], down[x.f])*2+1);
	}
	cout << ans << endl;
	
	
	
	return 0;
}

• Subtask 1: 22 / 22
• Subtask 2: 10 / 10
• Subtask 3: 31 / 31
• Subtask 4: 37 / 37