已含dfs和bfs，相关算法正在研究

代码

import java.util.*;public class Prim{public static void main(String[] args) {Graph graph=new Graph();graph.addVertex("A");graph.addVertex("B");graph.addVertex("C");graph.addVertex("D");graph.addVertex("E");graph.addEdge("A","B",1);graph.addEdge("A","E",2);graph.addEdge("B","C",2);graph.addEdge("B","F",2);graph.addEdge("C","D",2);graph.addEdge("D","F",2);graph.addEdge("E","F",2);System.out.println(graph.dfs());graph.addVertex("1");System.out.println(graph.dfs());}}
class Graph{public Boolean isConnected(){List<String> visited=new ArrayList<>();for(String v1:vertexs.keySet()){visited.add(v1);dfs(v1,visited);break;}return visited.size()==vertexs.size();}public void prim(){List<String> list=new ArrayList();putFirst(list);int size=vertexs.size();for(int i=1;i<size;i++){int min=Integer.MAX_VALUE;String next=null;for(String key:list){Map<String,Integer>neighbors=vertexs.get(key);for(Map.Entry<String,Integer> nbsentry:neighbors.entrySet()){if(!list.contains(nbsentry.getKey())){if(nbsentry.getValue()<min){min= nbsentry.getValue();next=nbsentry.getKey();}}}}if(next!=null){list.add(next);}}System.out.println(list);}public void putFirst(List<String> list){for(Map.Entry<String,Map<String,Integer>>entry:vertexs.entrySet()){String key=entry.getKey();Map<String,Integer> value=entry.getValue();list.add(key);break;}}private Map<String,Map<String,Integer>>vertexs;public Graph(){vertexs=new HashMap<>();}public void addVertex(String v1){if(!vertexs.containsKey(v1)){vertexs.put(v1,new HashMap<>());}}public void addEdge(String v1,String v2,int weight){if(!vertexs.containsKey(v1)){vertexs.put(v1,new HashMap<>());}vertexs.get(v1).put(v2,weight);if(!vertexs.containsKey(v2)){vertexs.put(v2,new HashMap<>());}vertexs.get(v2).put(v1,weight);}public Map<String,Integer> getNeighbors(String v1){return vertexs.get(v1);}public static void my_traverseNeighbors(Map<String, Integer> neighbors) {for (Map.Entry<String, Integer> entry : neighbors.entrySet()) {String vertex = entry.getKey();Integer weight = entry.getValue();System.out.println("顶点: " + vertex + ", 权重: " + weight);}}public void bfs(){List<String> visited=new ArrayList<>();for(String v1:vertexs.keySet()){bfs(v1,visited);}System.out.println("null");}private void bfs(String v1,List visited) {if(!visited.contains(v1)){System.out.print(v1+"->");visited.add(v1);}Map<String,Integer> map=vertexs.get(v1);for(Map.Entry<String,Integer>entry:map.entrySet()){String v2 = entry.getKey();if(!visited.contains(v2)){System.out.print(v2+"->");visited.add(v2);}}}public List dfs(){List<String> visited=new ArrayList<>();for(String v1:vertexs.keySet()){if(!visited.contains(v1)){visited.add(v1);dfs(v1,visited);}}return visited;}private List dfs(String v1, List<String> visited) {Map<String,Integer> map =vertexs.get(v1);for(Map.Entry<String,Integer>entry:map.entrySet()){String key=entry.getKey();if(!visited.contains(key)){visited.add(key);dfs(key,visited);}}return visited;}
}