johnson方法求所有节点对最短路径

package com.data.struct;import java.util.HashSet;import java.util.Iterator;import java.util.Random;import java.util.Set;public class Johnson {private Node[][] graphic;private Node[][] origonal;private Node [][]result;private Node s;private Set<Node> nextNodes = new HashSet<Node>();private Set<Node> addList = new HashSet<Node>();private Set<Node> removeList = new HashSet<Node>();public Johnson(int v, int e) {origonal = new Node[v][v];result=new Node[v][v];for (int i = 0; i < e; i++) {int v1 = new Random().nextInt(v);int v2 = new Random().nextInt(v);Node node = new Node();node.w = new Random().nextInt(v) + 1;node.d = Integer.MAX_VALUE - 1000;node.start = v1;node.end = v2;origonal[v1][v2] = node;}for (int i = 0; i < v; i++) {if (origonal[i][i] == null) {Node node = new Node();node.d = Integer.MAX_VALUE - 1000;node.w = 0;node.start = i;node.end = i;origonal[i][i] = node;} else {origonal[i][i].w = 0;}}graphic = new Node[v + 1][v + 1];for (int i = 0; i < origonal.length; i++) {for (int j = 0; j < origonal.length; j++) {graphic[i][j] = origonal[i][j];}}for (int i = 0; i < v + 1; i++) {Node node = new Node();node.start = origonal.length;node.d = Integer.MAX_VALUE - 1000;node.end = i;graphic[origonal.length][i] = node;}s = graphic[0][0];s.d = 0;}public Node[][] johnson() {if (!bellmanFord()) {System.out.println("matrix contain negtive cycle");return null;} else {printTmp();for (int i = 0; i < graphic.length; i++) {graphic[i][i].h = graphic[graphic.length - 1][i].d;}for (int i = 0; i < graphic.length; i++) {for (int j = 0; j < graphic.length; j++) {if (graphic[i][j] != null) {graphic[i][j].w = graphic[i][j].w + graphic[i][i].h- graphic[j][j].h;}}}for(int i=0;i<origonal.length;i++){dijkstra(origonal[i][i]);printResult();for (int j = 0; j < graphic.length; j++) {if (graphic[i][j] != null) {graphic[i][j].d = graphic[i][j].d - graphic[i][i].h+ graphic[j][j].h;}}}}return result;}public Node extractMin() {Iterator<Node> it = nextNodes.iterator();Node node = null;while (it.hasNext()) {if (node == null) {node = it.next();} else {Node n = it.next();if (n.d < node.d) {node = n;}}}return node;}public void dijkstra(Node s) {for(int i=0;i<origonal.length;i++){for(int j=0;j<origonal.length;j++){if(origonal[i][j]!=null){origonal[i][j].d=Integer.MAX_VALUE - 1000;}}}s.d=0;nextNodes.clear();for (int i = 0; i < origonal.length; i++) {nextNodes.add(origonal[i][i]);}for (int k = 0; k < origonal.length; k++) {if (k != s.start && origonal[s.start][k] != null) {relex(s, origonal[k][k]);}}nextNodes.remove(s);while (nextNodes.size() > 0) {Node node = extractMin();for (int k = 0; k < origonal.length; k++) {if (k != node.start && origonal[node.start][k] != null) {relex(node, origonal[k][k]);}}nextNodes.remove(node);}for(int i=0;i<origonal.length;i++){Node node=new Node();node.start=s.start;node.end=i;node.d=origonal[i][i].d;result[s.start][i]=node;}}public void relex(Node u, Node v) {if (graphic[v.end][v.end].d > u.d + graphic[u.start][v.start].w) {graphic[v.end][v.end].d = u.d + graphic[u.start][v.start].w;graphic[v.end][v.end].parent = u;addList.add(graphic[v.end][v.end]);System.out.println(graphic[v.end][v.end].start + "=>" + u.start+ "||" + graphic[v.end][v.end].d);}}public boolean bellmanFord() {s = graphic[graphic.length - 1][graphic.length - 1];s.d = 0;addList.clear();nextNodes.clear();removeList.clear();nextNodes.add(s);for (int k = 0; k < graphic.length; k++) {if (k != s.start && graphic[s.start][k] != null) {relex(s, graphic[k][k]);}}nextNodes.addAll(addList);nextNodes.remove(s);while (nextNodes.size() > 0) {addList.clear();removeList.clear();Iterator<Node> it = nextNodes.iterator();while (it.hasNext()) {Node node = it.next();for (int k = 0; k < graphic.length; k++) {if (k != node.start && graphic[node.start][k] != null) {relex(node, graphic[k][k]);}}removeList.add(node);}nextNodes.removeAll(removeList);nextNodes.addAll(addList);}for (int j = 0; j < graphic.length; j++) {for (int k = 0; k < graphic.length; k++) {if (j != k) {if (graphic[j][k] != null&& graphic[k][k].d > graphic[j][j].d+ graphic[j][k].w) {return false;}}}}return true;}public void printResult() {System.out.println("result:");for (int i = 0; i < result.length; i++) {for (int j = 0; j < result.length; j++) {if (result[i][j] != null) {System.out.print(result[i][j].d + " ");} else {System.out.print(" " + " ");}}System.out.println();}}public void printTmp() {System.out.println("tmp:");for (int i = 0; i < graphic.length; i++) {for (int j = 0; j < graphic.length; j++) {if (graphic[i][j] != null) {System.out.print(graphic[i][j].d + " ");} else {System.out.print(" " + " ");}}System.out.println();}}public void print() {System.out.println("origranal:");for (int i = 0; i < graphic.length; i++) {for (int j = 0; j < graphic.length; j++) {if (graphic[i][j] != null) {System.out.print(graphic[i][j].w + " ");} else {System.out.print(" " + " ");}}System.out.println();}Node[][] l = johnson();System.out.println("result:");for (int i = 0; i < l.length; i++) {for (int j = 0; j < l.length; j++) {if (l[i][j] != null) {System.out.print(l[i][j].d + " ");} else {System.out.print(" " + " ");}}System.out.println();}}private class Node {private int d;private int w;private int start;private int end;private Node parent;private int h;}public static void main(String[] args) {Johnson j = new Johnson(5, 20);j.print();}}