最小生成树之克鲁斯卡尔算法 ( java版)

1 图数据如下

二  Java代码

package leaning.graph;

import java.util.ArrayList;
import java.util.List;

import leaning.graph.entity.Edge;

/*
 * 克鲁斯卡尔最小生成树
 * */
public class KruskalMiniCostSpanningTree {
	//计数器
	private int counter = 0 ; 
	
	private int[] parent = new int[9];
	
	//边集合
	private List edgesList = new ArrayList();
	
	//最大Int整数,表示无穷大
	private int MAX_VALUE = Integer.MAX_VALUE;
	
	//定义节点
	private  String nodes[] = {"vo","v1","v2","v3","v4","v5","v6","v7","v8"};

	//定义地图变量
	private  int map[][] = new int[9][9]; 
	
	public KruskalMiniCostSpanningTree(){
		this.initMap();
		this.initEdages();
	}
	
	//初始化地图
	public void initMap(){
	  this.map[0] = new int[]{        0,       10,MAX_VALUE,MAX_VALUE,MAX_VALUE,       11,MAX_VALUE,MAX_VALUE,MAX_VALUE};
	  this.map[1] = new int[]{       10,        0,       18,MAX_VALUE,MAX_VALUE,MAX_VALUE,       16,MAX_VALUE,       12};
	  this.map[2] = new int[]{MAX_VALUE,MAX_VALUE,        0,       22,MAX_VALUE,MAX_VALUE,MAX_VALUE,MAX_VALUE,        8};
	  this.map[3] = new int[]{MAX_VALUE,MAX_VALUE,       22,        0,       20,MAX_VALUE,MAX_VALUE,       16,       21};
	  this.map[4] = new int[]{MAX_VALUE,MAX_VALUE,MAX_VALUE,       20,        0,       26,MAX_VALUE,        7,MAX_VALUE};
	  this.map[5] = new int[]{       11,MAX_VALUE,MAX_VALUE,MAX_VALUE,       26,        0,       17,MAX_VALUE,MAX_VALUE};
	  this.map[6] = new int[]{MAX_VALUE,       16,MAX_VALUE,MAX_VALUE,MAX_VALUE,       17,        0,       19,MAX_VALUE};
	  this.map[7] = new int[]{MAX_VALUE,MAX_VALUE,MAX_VALUE,       16,        7,MAX_VALUE,       19,        0,MAX_VALUE};
	  this.map[8] = new int[]{MAX_VALUE,       12,        8,       21,MAX_VALUE,MAX_VALUE,MAX_VALUE,MAX_VALUE,         0};
	
	}
	
	//初始化边和权的list集合
	public void initEdages(){
		
		Edge v0 = new Edge(4,7,7);
		Edge v1 = new Edge(2,8,8);
		Edge v2 = new Edge(0,1,10);
		Edge v3 = new Edge(0,5,11);
		Edge v4 = new Edge(1,8,12);
		Edge v5 = new Edge(3,7,16);
		Edge v6 = new Edge(1,6,16);
		Edge v7 = new Edge(5,6,17);
		Edge v8 = new Edge(1,2,18);
		Edge v9 = new Edge(6,7,19);
		Edge v10 = new Edge(3,4,20);
		Edge v11 = new Edge(3,8,21);
		Edge v12 = new Edge(2,3,22);
		Edge v13 = new Edge(3,6,24);
		Edge v14 = new Edge(4,5,26);
		
		this.edgesList.add(v0);
		this.edgesList.add(v1);
		this.edgesList.add(v2);
		this.edgesList.add(v3);
		this.edgesList.add(v4);
		this.edgesList.add(v5);
		this.edgesList.add(v6);
		this.edgesList.add(v7);
		this.edgesList.add(v8);
		this.edgesList.add(v9);
		this.edgesList.add(v10);
		this.edgesList.add(v11);
		this.edgesList.add(v12);
		this.edgesList.add(v13);
		this.edgesList.add(v14);
	}
	
	//克鲁斯卡尔算法
	public void kruskal(){
		int n = - 1, m = -1 ,begin,end;
		for(int i=0 ; i < this.edgesList.size() ;i++){ //遍历得到每一条边
			begin =  this.edgesList.get(i).getBegin();
			end = this.edgesList.get(i).getEnd();
			n = this.find(begin);
			m = this.find(end);
			if(n!=m){ //说明没有闭合线路
				this.counter++;
				this.parent[n] = m;
				System.out.println(" 第  "+this.counter+" 条边为 : ( "+this.nodes[this.edgesList.get(i).getBegin()]+" , "+this.nodes[this.edgesList.get(i).getEnd()]+" ) = "+this.edgesList.get(i).getWeight()+" ");
			}
		}
	}
	
	
	public int find(int index){
		while(this.parent[index] > 0  ){
			index = this.parent[index];
		}
		return index;
	}
	

	
	public static void main(String[] args) {
		KruskalMiniCostSpanningTree kruskalMiniCostSpanningTree = new KruskalMiniCostSpanningTree();
		kruskalMiniCostSpanningTree.kruskal();
		
	}

}

package leaning.graph.entity;

/*
 * 克鲁斯卡尔->最小生成树边实体
 * */
public class Edge {
	
   private int begin;
   private int end;
   private int weight;
   
   public Edge(int begin, int end, int weight) {
	    this.begin = begin;
		this.end = end;
		this.weight = weight;
   }
	
	public int getBegin() {
		return begin;
	}
	
	public void setBegin(int begin) {
		this.begin = begin;
	}
	
	public int getEnd() {
		return end;
	}
	
	public void setEnd(int end) {
		this.end = end;
	}
	
	public int getWeight() {
		return weight;
	}
	
	public void setWeight(int weight) {
		this.weight = weight;
	}
	   
   
   
}

3 运算结果如下