Question

遇到Dijkstra算法问题，

试图在两个城市之间找到路径。

以下是我的java课程......

ConnectedVertices类是顶点数组的位置......

我使用了一个arraylist来生成城市之间的连接

package main;

public class Edges
{
    public String u;
    public String v;
    public String d;

    public Edges(String city1, String city2, String distance)
    {
        u = city1;
        v = city2;
        d = distance;
    }
    public Edges(int city1, int city2, int distance)
    {
        u = String.valueOf(city1);
        v = String.valueOf(city2);
        d = String.valueOf(distance);
    }
}

这里是顶点和arraylist来表示图形。

package main;

import java.util.ArrayList;
import java.util.PriorityQueue;
import java.util.List;
import java.util.Collections;
import org.apache.commons.lang3.ArrayUtils;

public class ConnectedVertices
{
   public String[] vertice = { "lagos", "ikeja", "Benin city", "Agbor", "Sagamu", "Ibadan",
                        "Iwo", "Osogbo", "Abuja", "Kafanchan", "Jos", "Bauchi", "Gombe",
                       "Biu", "N’djamena", "Dikwa", "Maiduguri", "Damaturu", "Potiskum", 
                       "Azare", "Dutse", "Wudil", "Kano", "Kusada", "Chafe", "Gusau",
                       "Talata-Mafara", "Kaduna", "Zaria", "Ikire", "Ondo", "Sapele", "Warri",
                       "Yenegoa", "Portharcourt", "Aba",  "Ikot-ekpene", "Oturkpo", "Makurdi",
                       "Idah", "Lokoja", "Abaji", "Umuahia", "Owerri", "Akwa", "Damboa", 
                       "Egbe-ejiba", "katsina", "Sokoto", "Ore", "Calabar", "Agbor", "Onitsha",
                       "Lafia", "Enugu"};

   //public ArrayList<Edges> edges = new ArrayList();
   ArrayList<Edges> edges = new ArrayList<Edges>();

   public ConnectedVertices()
   {
       AddEdges();
   }

   class Vertex implements Comparable<Vertex>
   {
       public final String name;
       //public Edge[] adjacencies;
       public double minDistance = Double.POSITIVE_INFINITY;
       public Vertex previous;
       public Vertex(String argName) { name = argName; }
       public String toString() { return name; }
       public int compareTo(Vertex other)
       {
           return Double.compare(minDistance, other.minDistance);
       }

   }

   @SuppressWarnings("unchecked")
public void AddEdges()
   {
       edges.add(new Edges(0, 1, 46));
       edges.add(new Edges(1, 4, 55));
       edges.add(new Edges(1, 2, 304));
       edges.add(new Edges(2, 49, 107));
       edges.add(new Edges(2, 31, 63));
       edges.add(new Edges(2, 3, 70));
       edges.add(new Edges(3, 51, 79));
       edges.add(new Edges(4, 5, 84));
       edges.add(new Edges(5, 6, 46));
       edges.add(new Edges(5, 29, 31));
       edges.add(new Edges(6, 7, 48));
       edges.add(new Edges(7, 46, 154));
       edges.add(new Edges(8, 46, 388));
       edges.add(new Edges(8, 9, 171));
       edges.add(new Edges(8, 27, 187));
       edges.add(new Edges(9, 10, 110));
       edges.add(new Edges(10, 11, 130));
       edges.add(new Edges(10, 52, 206));
       edges.add(new Edges(11, 12, 157));
       edges.add(new Edges(12, 13, 126));
       edges.add(new Edges(13, 45, 101));
       edges.add(new Edges(14, 15, 177));
       edges.add(new Edges(15, 16, 142));
       edges.add(new Edges(16, 17, 133));
       edges.add(new Edges(17, 18, 99));
       edges.add(new Edges(18, 19, 148));
       edges.add(new Edges(19, 20, 106));
       edges.add(new Edges(20, 21, 77));
       edges.add(new Edges(21, 22, 38));
       edges.add(new Edges(22, 23, 112));
       edges.add(new Edges(22, 24, 245));
       edges.add(new Edges(23, 47, 94));
       edges.add(new Edges(24, 25, 41));
       edges.add(new Edges(25, 26, 95));
       edges.add(new Edges(26, 48, 111));
       edges.add(new Edges(27, 28, 80));
       edges.add(new Edges(27, 8, 185));
       edges.add(new Edges(27, 10, 217));
       edges.add(new Edges(28, 22, 157));
       edges.add(new Edges(29, 30, 109));
       edges.add(new Edges(30, 49, 96));
       edges.add(new Edges(31, 32, 40));
       edges.add(new Edges(32, 33, 137));
       edges.add(new Edges(33, 34, 116));
       edges.add(new Edges(34, 35, 61));
       edges.add(new Edges(35, 36, 41));
       edges.add(new Edges(36, 50, 109));
       edges.add(new Edges(36, 42, 50));
       edges.add(new Edges(37, 38, 109));
       edges.add(new Edges(37, 53, 156));
       edges.add(new Edges(38, 52, 101));
       edges.add(new Edges(39, 51, 142));
       edges.add(new Edges(39, 40, 122));
       edges.add(new Edges(40, 41, 88));
       edges.add(new Edges(41, 8, 113));
       edges.add(new Edges(42, 53, 126));
       edges.add(new Edges(43, 51, 42));
       edges.add(new Edges(43, 34, 106));
       edges.add(new Edges(44, 51, 46));
       edges.add(new Edges(44, 53, 129));
       edges.add(new Edges(45, 16, 88));
       System.out.println("Contents of all locations: " + edges.size());
   }

   public String Connected(String first, String second)
   {
       int p,a;
       for (int i = 1; i <= edges.size(); i++) {
           for (int j = 0; j < edges.size(); j++) {
            //this is as far i could go...
        }
       }


   }

}

请帮助......

Answer 1

您需要对我认为的算法进行更多解释：

   int p,a;
   for (int i = 1; i <= edges.size(); i++) {
       for (int j = 0; j < edges.size(); j++) {
        //this is as far i could go...
    }
   }

首先阅读维基页面，其中包含代码示例：

https://en.wikipedia.org/wiki/Dijkstra%27s_algorithm

然后看看（它使用队列），我无法复制代码，它没有许可证。请点击链接

https://github.com/iensen/Algorithms/blob/master/Graphs/Djikstra.java

遇到Dijkstra java代码问题

1 个答案: