java查找图中两点之间所有路径

本文实例为大家分享了java查找图中两点之间所有路径的具体代码，基于邻接表，供大家参考，具体内容如下

图类：

package graph1;

import java.util.LinkedList;

import graph.Graph.edgeNode;

public class Graph {

class EdgeNode{
int adjvex;
EdgeNode nextEdge;
}

class VexNode{
int data;
EdgeNode firstEdge;
boolean isVisted;
public boolean isVisted() {
return isVisted;
}
public void setVisted(boolean isVisted) {
this.isVisted = isVisted;
}

}

VexNode[] vexsarray ;
int[] visited = new int[100];
boolean[] isVisited = new boolean[100];

public void linkLast(EdgeNode target,EdgeNode node) {
while (target.nextEdge!=null) {
target=target.nextEdge;
}
target.nextEdge=node;
}

public int getPosition(int data) {
for(int i=0;i<vexsarray.length;i++) {
if (data==vexsarray[i].data) {
return i;
}
}
return -1;
}

public void buildGraph(int[] vexs,int[][] edges ) {
int vLen = vexs.length;
int eLen = edges.length;
vexsarray = new VexNode[vLen];

for(int i=0;i<vLen;i++) {
vexsarray[i] = new VexNode();
vexsarray[i].data = vexs[i];
vexsarray[i].firstEdge = null;
}

for(int i=0;i<eLen;i++) {

int a = edges[i][0];
int b = edges[i][1];

int start = getPosition(a);
int end = getPosition(b);

EdgeNode edgeNode = new EdgeNode();
edgeNode.adjvex = end;

if (vexsarray[start].firstEdge == null) {
vexsarray[start].firstEdge = edgeNode;
} else {
linkLast(vexsarray[start].firstEdge,edgeNode);
}
}
}

public void printGraph() {
for(int i=0;i<vexsarray.length;i++) {
System.out.printf("%d--",vexsarray[i].data);
EdgeNode node = vexsarray[i].firstEdge;
while (node!=null) {
System.out.printf("%d(%d)--",node.adjvex,vexsarray[node.adjvex].data);
node = node.nextEdge;
}
System.out.println("\n");
}
}

算法：

package graph1;

import java.util.HashMap;
import java.util.Map;
import java.util.Stack;

import javax.swing.plaf.synth.SynthStyle;

import graph1.Graph.EdgeNode;

public class FindALlPath {

//代表某节点是否在stack中,避免产生回路
public Map<Integer,Boolean> states=new HashMap();

//存放放入stack中的节点
public Stack<Integer> stack=new Stack();

//打印stack中信息,即路径信息
public void printPath(){
StringBuilder sb=new StringBuilder();
for(Integer i :stack){
sb.append(i+"->");
}
sb.delete(sb.length()-2,sb.length());
System.out.println(sb.toString());
}

//得到x的邻接点为y的后一个邻接点位置,为-1说明没有找到
public int getNextNode(Graph graph,int x,int y){
int next_node=-1;
EdgeNode edge=graph.vexsarray[x].firstEdge;
if(null!=edge&&y==-1){
int n=edge.adjvex;
//元素还不在stack中
if(!states.get(n))
return n;
return -1;
}

while(null!=edge){
//节点未访问
if(edge.adjvex==y){
if(null!=edge.nextEdge){
next_node=edge.nextEdge.adjvex;

if(!states.get(next_node))
return next_node;
}
else
return -1;
}
edge=edge.nextEdge;
}
return -1;
}

public void visit(Graph graph,int x,int y){
//初始化所有节点在stack中的情况
for(int i=0;i<graph.vexsarray.length;i++){
states.put(i,false);
}
//stack top元素
int top_node;
//存放当前top元素已经访问过的邻接点,若不存在则置-1,此时代表访问该top元素的第一个邻接点
int adjvex_node=-1;
int next_node;
stack.add(x);
states.put(x,true);

while(!stack.isEmpty()){
top_node=stack.peek();
//找到需要访问的节点
if(top_node==y){
//打印该路径
printPath();
adjvex_node=stack.pop();
states.put(adjvex_node,false);
}
else{
//访问top_node的第advex_node个邻接点
next_node=getNextNode(graph,top_node,adjvex_node);
if(next_node!=-1){
stack.push(next_node);
//置当前节点访问状态为已在stack中
states.put(next_node,true);
//临接点重置
adjvex_node=-1;
}
//不存在临接点，将stack top元素退出
else{
//当前已经访问过了top_node的第adjvex_node邻接点
adjvex_node=stack.pop();
//不在stack中
states.put(adjvex_node,false);
}
}
}
}

}

测试类：

package graph1;

import java.util.Iterator;

import graph1.Graph.VexNode;

public class Tset2 {

public static void main(String[] args) {

int[] vexs = {0,1,2,3,4};
int[][] edges = {
{0,1},
{0,3},
{1,0},
{1,2},
{2,1},
{2,3},
{2,4},
{3,0},
{3,2},
{3,4},
{4,2},
{4,3},

};
Graph graph = new Graph();
graph.buildGraph(vexs, edges);
graph.printGraph();

FindALlPath findALlPath = new FindALlPath();
findALlPath.visit(graph, 4, 0);

}

}

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持脚本之家。

您可能感兴趣的文章:

• java查找无向连通图中两点间所有路径的算法
• java计算图两点之间的所有路径
• java搜索无向图中两点之间所有路径的算法