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Java实现有向图找循环(深度优先-递归)

    博客分类:
  • Java
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目前写了个有向图深度优先递归算法,求出所有环路。

作为一个实际需求的前奏。

 

循环的单位叫做Serv

服务与服务关系,模拟数据库里面存放的二元关系,用ServRel类代替。

public class GraphFindCycle {
	public List servList;
	
	public void setServList(List servList){
		this.servList = servList;
	}
	
	class ServRel{
		public String useServId;
		public String providerServId;
		public double amount;
	}
	
	class Serv{
		public String servId;
		public List refServ = new ArrayList();
	}
	
	public List findRefServ(String servId,List servRelList){
		List refServList = new ArrayList();
		for(int i=0;i<servRelList.size();i++){
			ServRel rel = (ServRel)servRelList.get(i);
			if(servId.equals(rel.useServId)){
				refServList.add(rel.providerServId);
			}
		}
		return refServList;
	}
	
	class CycleServ{
		public List cycleServList;
	}
	
	public void findCycleServ(String servId,String cyclePath,List servRelList){
			String id = servId;
			List refServList = findRefServ(servId,servRelList);
			if(!(refServList.size()>0)){
				return;
			}
			else if(cyclePath.indexOf(servId)>0){
				System.out.println(cyclePath+","+id);
				return;
			}
			else{
				cyclePath = cyclePath+","+id;
				for(int j=0;j<refServList.size();j++){
					String childServId = (String)refServList.get(j);
					findCycleServ(childServId,cyclePath,servRelList);
				}
			}
	}
	
	
	public static void main(String[] args) {
		GraphFindCycle gfc = new GraphFindCycle();
		List servList = new ArrayList();
		servList.add("A");
		servList.add("B");
		servList.add("C");
		servList.add("D");
		servList.add("E");
		servList.add("F");
		
		List servRelList = new ArrayList();
		ServRel sr = gfc.new ServRel();
		sr.useServId = "A";
		sr.providerServId = "B";
		servRelList.add(sr);
		ServRel sr1 = gfc.new ServRel();
		sr1.useServId = "B";
		sr1.providerServId = "A";
		servRelList.add(sr1);
		ServRel sr2 = gfc.new ServRel();
		sr2.useServId = "A";
		sr2.providerServId = "C";
		servRelList.add(sr2);
		ServRel sr3 = gfc.new ServRel();
		sr3.useServId = "B";
		sr3.providerServId = "D";
		servRelList.add(sr3);
		ServRel sr4 = gfc.new ServRel();
		sr4.useServId = "E";
		sr4.providerServId = "A";
		servRelList.add(sr4);
		ServRel sr5 = gfc.new ServRel();
		sr5.useServId = "F";
		sr5.providerServId = "B";
		servRelList.add(sr5);
		
		//System.out.println(servRelList.size());
		for(int i=0;i<servList.size();i++){
			String servId = (String)servList.get(i);
			gfc.findCycleServ(servId,"",servRelList);
		}
	}

}

 

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