优先队列优化的 Dijkstra算法

import java.util.ArrayList;
import java.util.PriorityQueue;
import java.util.Scanner;

public class Main {
	PriorityQueue pq;
	ArrayList []adj;
	int []distTo;
	int n, m;
	public static void main(String[] args) {
		new Main().run();
	}
	public void run() {
		Scanner in = new Scanner(System.in);	
		while(in.hasNext()) {
			n = in.nextInt();
			m = in.nextInt();
			if(n == 0 && m == 0) {
				break;
			}
			distTo = new int[n+1];
			pq = new PriorityQueue<>();
			adj = new ArrayList[n+1];
			for(int i = 1; i <= n; i++ ) {
				adj[i] = new ArrayList<>();
			}
			
			for(int i = 0; i < m; i++ ) {
				int u = in.nextInt();
				int v = in.nextInt();
				int w = in.nextInt();
				adj[u].add(new Edge(u, v, w));
				adj[v].add(new Edge(v, u, w));
			}
			dijkstra();
			System.out.println(distTo[n]);	
		}
		
	}
	public void dijkstra() {
		for(int i = 1; i <= n; i++ ) {
			distTo[i] = Integer.MAX_VALUE;
		}
		distTo[1] = 0;
		pq.offer(new dist(1, 0));
		
		while(!pq.isEmpty()) {
			int v = pq.poll().v;
			for(Edge e: adj[v]) {
				int w = e.v;
				if(distTo[w] > distTo[v] + e.w) {
					distTo[w] = distTo[v] + e.w;
					pq.offer(new dist(w, distTo[w]));
				}
			}
		}
	}

}
	
	
class Edge{
	int u, v, w;
	public Edge(int u, int v, int w) {
		this.u = u;
		this.v = v;
		this.w = w;
	}
}

class dist implements Comparable{//顶点v 与 与distTo[v]->w
	int v;
	int w;
	public dist(int v, int w) {
		this.v = v;
		this.w = w;
	}
	public int compareTo(dist o) {
		return w > o.w ? 1 : -1;
	}
}

临接矩阵的Dijkstra快速写法

for(int i = 1; i <= n; i++ ) {
			dist[i] = map[1][i];
		}
		visit[1] = true;
		while(true) {
			int v = -1;
			for(int u = 1; u <= n; u++ ) {
				if(!visit[u] && (v == -1 || dist[u] < dist[v])) {
					v = u;
				}
			}
			if(v == -1)
				break;
			visit[v] = true;
			for(int w = 1; w <= n; w++ ) {
				if(map[v][w] < INF)
					dist[w] = Math.min(dist[w], dist[v]+map[v][w]);
			}
		}