Submission #930683

#	Time	Username	Problem	Language	Result	Execution time	Memory
930683		dubabuba	Airplane (NOI23_airplane)	C++14	0 / 100	134 ms	15256 KiB

Main

#include <bits/stdc++.h>
using namespace std;

typedef pair<int, int> pii;
#define ff first
#define ss second
#define MP make_pair

const int mxn = 2e5 + 10;
vector<int> adj[mxn];
int a[mxn], n, m;
int dis[2][mxn];
int alt[2][mxn];

int main() {
	cin >> n >> m;
	for(int i = 1; i <= n; i++)
		cin >> a[i];
	for(int i = 0; i < m; i++) {
		int u, v;
		cin >> u >> v;
		adj[u].push_back(v);
		adj[v].push_back(u);
	}

	memset(dis[0], -1, sizeof dis[0]);
	memset(dis[1], -1, sizeof dis[1]);
	memset(alt[0], -1, sizeof alt[0]);
	memset(alt[1], -1, sizeof alt[1]);

	priority_queue<pair<pii, int>> pq;
	pq.push(MP(MP(0, 0), 1));
	while(pq.size()) {
		int d = -pq.top().ff.ff;
		int h = -pq.top().ff.ss;
		int u = pq.top().ss;
		pq.pop();

		if(dis[0][u] > -1) continue;
		dis[0][u] = d;
		alt[0][u] = h;

		for(int v : adj[u]) {
			if(dis[0][v] > -1) continue;
			if(h >= a[v]) pq.push(MP(MP(-(d + 1), -h), v));
			else pq.push(MP(MP(-(d + a[v] - h), -a[v]), v));
		}
	}

	pq.push(MP(MP(0, 0), n));
	while(pq.size()) {
		int d = -pq.top().ff.ff;
		int h = -pq.top().ff.ss;
		int u = pq.top().ss;
		pq.pop();

		if(dis[1][u] > -1) continue;
		dis[1][u] = d;
		alt[1][u] = h;

		for(int v : adj[u]) {
			if(dis[1][v] > -1) continue;
			if(h >= a[v]) pq.push(MP(MP(-(d + 1), -h), v));
			else pq.push(MP(MP(-(d + a[v] - h), -a[v]), v));
		}
	}

	int ans = INT_MAX;
	for(int i = 1; i <= n; i++)
	if(alt[0][i] == alt[1][i] && alt[0][i] != -1)
		ans = min(ans, dis[0][i] + dis[1][i]);

	cout << ans << endl;
	return 0;
}

• Subtask 1: 0 / 22
• Subtask 2: 0 / 10
• Subtask 3: 0 / 31
• Subtask 4: 0 / 37