java最短路径算法开源包,用java编写的一个迪杰斯特拉算法（单源最短路径算法，Dijkstra算法）。，单源dijkstra,package Test...

用java编写的一个迪杰斯特拉算法(单源最短路径算法，Dijkstra算法)。，单源dijkstra,package Testpackage Test;import java.util.TreeMap;import java.util.ArrayList;import java.io.BufferedReader;import java.io.InputStreamReader;import java.io.IOException;class Point { private int id;// 点的id private boolean flag = false;// 标志是否被遍历 int sum;// 记录总的点个数 private TreeMap thisPointMap = new TreeMap();// 该点到各点的距离。 BufferedReader bufr = new BufferedReader(new InputStreamReader(System.in)); Point(int sum) { // 构造函数 带有顶点个数 this.sum = sum; } public void setId(int id) {// 设置顶点id this.id = id; } public int getId() {// 获得顶点id return this.id; } public void changeFlag() {// 修改访问状态。 this.flag = true; } public boolean isVisit() {// 查看访问状态 return flag; } public void setLenToOther()throws IOException{// 初始化改点到各顶点的距离。 System.out.println("=======请输入顶点" + (this.id + 1) + "至其他各顶点的边距======="); for (int i = 0; i < sum; i++) { if (i == this.id) thisPointMap.put(this.id, 0); else { System.out.print("至 顶点" + (i + 1) + " 的距离 ："); boolean flag =true; int len = 0; while(flag){ try { len = Integer.valueOf(bufr.readLine()); flag = false; } catch (NumberFormatException e) { System.out.print("输入有误，请重新输入："); } }; thisPointMap.put(i, len); } } } // 该点到顶尖id的 距离。 public int lenToPointId(int id) { return thisPointMap.get(id); }}class Dijkstra { public static void main(String[] args)throws IOException { ArrayList point_arr = new ArrayList();// 存储点集合 BufferedReader bufr = new BufferedReader(new InputStreamReader(System.in)); System.out.print("请输入顶点个数： "); int sum = 0; boolean flag =true; while(flag){ try { sum = Integer.valueOf(bufr.readLine()); flag = false; } catch (NumberFormatException e) { System.out.print("输入有误，请重新输入："); } }; for (int i = 0; i < sum; i++) {// 初始化 Point p = new Point(sum); p.setId(i); p.setLenToOther(); point_arr.add(p); } System.out.print("请输入起始顶点 id ："); boolean flag2 =true; int start = 0; while(flag2){ try { start = Integer.valueOf(bufr.readLine())-1; if(start > sum-1 || start < 0) throw new NumberFormatException(); flag2 = false; }catch (NumberFormatException e) { System.out.print("输入有误，请重新输入："); } }; showDijkstra(point_arr, start);// 单源最短路径遍历 } public static void showDijkstra(ArrayList arr, int i) { System.out.print("顶点" + (i + 1)); arr.get(i).changeFlag(); Point p1 = getTopointMin(arr, arr.get(i)); if (p1 == null) return; int id = p1.getId(); showDijkstra(arr, id); } public static Point getTopointMin(ArrayList arr, Point p) { Point temp = null; int minLen = Integer.MAX_VALUE; for (int i = 0; i < arr.size(); i++) { // 当已访问 或 者是自身或者无该路径时跳过。 if (arr.get(i).isVisit() || arr.get(i).getId() == p.getId() || p.lenToPointId(i) < 0) continue; else { if (p.lenToPointId(i) < minLen) { minLen = p.lenToPointId(i); temp = arr.get(i); } } } if (temp == null) return temp; else System.out.print(" @--" + minLen + "--> "); return temp; }}{--