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Copy pathWeightedGraph.java
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195 lines (164 loc) · 5.71 KB
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package advance;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.PriorityQueue;
public class WeightedGraph<V> extends AbstractGraph<V> {
private List<PriorityQueue<WeightedEdge>> queues;
public WeightedGraph(int[][] edges,V[] vertices){
super(edges, vertices);
creatQueue(edges,vertices.length);
}
public WeightedGraph(List<WeightedEdge> edges,List<V> vertices){
super((List)edges,vertices);
creatQueue(edges,vertices.size());
}
public WeightedGraph(int[][] edges,int numberOfVertices){
super(edges, numberOfVertices);
creatQueue(edges,numberOfVertices);
}
public WeightedGraph(List<WeightedEdge> edges,int numberOfVertices){
super((List)edges,numberOfVertices);
creatQueue(edges,numberOfVertices);
}
private void creatQueue(List<WeightedEdge> edges,int numberOfVertices){
queues=new ArrayList<PriorityQueue<WeightedEdge>>();
for(int i=0;i<numberOfVertices;i++)
queues.add(new PriorityQueue<WeightedEdge>());
for(int i=0;i<edges.size();i++){
queues.get(edges.get(i).u).offer(edges.get(i));
}
}
private void creatQueue(int[][] edges,int numberOfVertices){
queues=new ArrayList<PriorityQueue<WeightedEdge>>();
for(int i=0;i<numberOfVertices;i++)
queues.add(new PriorityQueue<WeightedEdge>());
for(int i=0;i<edges.length;i++){
queues.get(edges[i][0]).offer(new WeightedEdge(edges[i][0], edges[i][1], edges[i][2]));
}
}
public void printWeightedEdges(){
for(int i=0;i<queues.size();i++){
System.out.print("顶点"+i+":");
for(WeightedEdge edge:queues.get(i)){
System.out.println("("+edge.u+","+edge.v+","+edge.weight+")");
}
System.out.println();
}
}
public MST getMinimumSpanningTree(){
return getMinimumSpanningTree(0);
}
public MST getMinimumSpanningTree(int startingIndex){
List<Integer> T=new ArrayList<>();
T.add(startingIndex);
int numberOfVertices=vertices.size();
int[] parent=new int[numberOfVertices];
Arrays.fill(parent, -1);
int totalWeight=0;
// List<PriorityQueue<WeightedEdge>> queues=deepClone(this.queues);
while(T.size()<numberOfVertices){
int v=-1;
double smallestWeight=Double.MAX_VALUE;
//遍历已在树中的所有顶点，找到一个最小边，将它添加到树中
for(int u:T){
//
for(WeightedEdge edge:queues.get(u)){
if(!T.contains(edge.v)){
if(edge.weight<smallestWeight){
smallestWeight=edge.weight;
parent[edge.v]=u;
v=edge.v;
}
}
}
}
T.add(v);
totalWeight+=smallestWeight;
}
return new MST(startingIndex, parent, T, totalWeight);
}
// private List<PriorityQueue<WeightedEdge>> deepClone(List<PriorityQueue<WeightedEdge>> queues){
//
//
// return null;
// }
public class MST extends Tree{
private int totalWeight;
public MST(int root, int[] parent, List<Integer> searchOrders,int totalWeight) {
super(root, parent, searchOrders);
this.totalWeight=totalWeight;
// TODO Auto-generated constructor stub
}
public int getTotalWeight(){
return totalWeight;
}
}
public ShortestPathTree getShortestPath(int sourceIndex){
List<Integer> T=new ArrayList<>();
T.add(sourceIndex);
int numberOfVertices=vertices.size();
int[] parent=new int[numberOfVertices];
parent[sourceIndex]=-1;
int[] costs=new int[numberOfVertices];
Arrays.fill(costs, Integer.MAX_VALUE);
costs[sourceIndex]=0;
while(T.size()<numberOfVertices){
int v=-1;
int smallestCost=Integer.MAX_VALUE;
//两层循环可以找到一个加入树中的点
for(int i=0;i<numberOfVertices;i++){
if(costs[i]<Integer.MAX_VALUE){
for(WeightedEdge edge:queues.get(i)){
if(!T.contains(edge.v)){
if((costs[i]+edge.weight)<smallestCost){
v=edge.v;
smallestCost=costs[i]+edge.weight;
parent[v]=i;
}
}
}
}
}
T.add(v);
costs[v]=smallestCost;
}
return new ShortestPathTree(sourceIndex, parent, T, costs);
}
public class ShortestPathTree extends Tree{
private int[] costs;
public ShortestPathTree(int root, int[] parent, List<Integer> searchOrders,int[] costs) {
super(root, parent, searchOrders);
this.costs=costs;
// TODO Auto-generated constructor stub
}
public int getCost(int v){
return costs[v];
}
public void printAllPaths(){
for(int i=0;i<costs.length;i++){
printPath(i);
System.out.println("cost"+costs[i]);
}
}
}
public List<PriorityQueue<WeightedEdge>> getWeightedEdges(){
return queues;
}
public class WeightedEdge extends AbstractGraph.Edge implements Comparable<WeightedEdge>{
public int weight;
public WeightedEdge(int u,int v,int weight){
super(u, v);
this.weight=weight;
}
public int compareTo(WeightedEdge edge){
if(weight>edge.weight)
return 1;
else if(weight==edge.weight)
return 0;
else {
return -1;
}
}
}
}