最小生成树----克鲁斯卡尔算法----java版

 

踉踉跄跄写出来了,原理我基本懂了,但是感觉有点讲不出来,这里只贴一下代码:

图如上:

package cn.nrsc.graph;

/**
 * 
 * @author 孙川 最小生成树-克鲁斯卡尔算法
 *
 */
public class Graph_Kruskal {

	// ------ 边实体----------
	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;
		}

	}
	// ------ 边实体----------

	private Edge[] edges; // 边数组
	private int edgeSize; // 边的数量

	public Graph_Kruskal(int edgeSize) {
		this.edgeSize = edgeSize;
		this.edges = new Edge[edgeSize];
	}

	// 生成边数组
	public void createEdges() {
		edges[0] = new Edge(4, 7, 7);
		edges[1] = new Edge(2, 8, 8);
		edges[2] = new Edge(0, 1, 10);
		edges[3] = new Edge(0, 5, 11);
		edges[4] = new Edge(1, 8, 12);
		edges[5] = new Edge(3, 7, 16);
		edges[6] = new Edge(1, 6, 16);
		edges[7] = new Edge(5, 6, 17);
		edges[8] = new Edge(1, 2, 18);
		edges[9] = new Edge(6, 7, 19);
		edges[10] = new Edge(3, 4, 20);
		edges[11] = new Edge(3, 8, 21);
		edges[12] = new Edge(2, 3, 22);
		edges[13] = new Edge(3, 6, 24);
		edges[14] = new Edge(4, 5, 26);

	}

	// 克鲁斯卡尔算法
	public void Kruskal() {
		// 初始化"回环判断"数组
		int[] fromTo = new int[edgeSize];
		int sum = 0;

		// 从权重最小的边开始,如果没有形成回环,则该边是满足条件的边
		for (int i = 0; i < edgeSize; i++) {
			int n = find(fromTo, edges[i].begin);
			int m = find(fromTo, edges[i].end);
			if (n != m) {
				fromTo[n] = m;
				System.out.println();
				System.out.println("起始顶点:" + edges[i].begin + "---->结束顶点:" + edges[i].end);
				sum += edges[i].weight;
			} else {
				System.out.println("第" + i + "条边出现了回环");
			}
		}
		System.out.println("最小生成树的总距离为:" + sum);

	}
	
	private int find(int[] p, int f) {
		System.out.print("|||***> " + f);
		while (p[f] > 0) {
			f = p[f];
			System.out.print("----> " + f);
		}
		return f;
	}

	public static void main(String[] args) {
		Graph_Kruskal graph = new Graph_Kruskal(15);
		graph.createEdges();
		graph.Kruskal();
	}
}

运行结果也贴一下: