[Function add]

1.Add degree to graph.

Author: Seanforfun

Diff for: Algorithm(4th_Edition)/src/ca/mcmaster/chapter/four/graph/DFSCC.java

@@ -58,5 +58,6 @@ public static void main(String[] args) throws FileNotFoundException {
 				sb.append(v + " ");
 			System.out.println(sb.toString());
 		}
+		
 	}
 }

Diff for: Algorithm(4th_Edition)/src/ca/mcmaster/chapter/four/graph/Graph.java

@@ -1,7 +1,5 @@
 package ca.mcmaster.chapter.four.graph;
 
-import java.awt.DisplayMode;
-
 public interface Graph {
 	/**
 	 * @Description: Get the vertex number.
@@ -35,7 +33,7 @@ public interface Graph {
 	 */
 	static Integer degree(Graph G, int V){
 		Integer degree = new Integer(0);
-		for(int w : G.adj(V)) degree++;
+		for(@SuppressWarnings("unused") int w : G.adj(V)) degree++;
 		return degree;
 	}
 

Diff for: Algorithm(4th_Edition)/src/ca/mcmaster/chapter/four/graph/SymbolGraphImpl.java

@@ -69,8 +69,13 @@ public static void main(String[] args) throws FileNotFoundException {
 		for(int v = 0; v < vertexNum; v++){
 			StringBuilder sb = new StringBuilder(symbolGraphImpl.name(v) + " -> ");
 			for(int w : graph.adj(v))
-				sb.append(symbolGraphImpl.name(w) + " ");
-			System.out.println(sb.toString());
+				sb.append(symbolGraphImpl.name(w) + "|");
+		}
+		BreadthFirstPath bfs = new BreadthFirstPath(graph, symbolGraphImpl.index("Bacon, Kevin"));
+		Iterable<Integer> pathTo = bfs.pathTo(symbolGraphImpl.index("Kidman, Nicole"));
+		System.out.println("Bacon, Kevin");
+		for(int w : pathTo){
+			System.out.println(symbolGraphImpl.name(w));
 		}
 	}
 }

Diff for: DataStructrue/Graph/SymbolGraphImpl.java

@@ -69,8 +69,13 @@ public static void main(String[] args) throws FileNotFoundException {
 		for(int v = 0; v < vertexNum; v++){
 			StringBuilder sb = new StringBuilder(symbolGraphImpl.name(v) + " -> ");
 			for(int w : graph.adj(v))
-				sb.append(symbolGraphImpl.name(w) + " ");
-			System.out.println(sb.toString());
+				sb.append(symbolGraphImpl.name(w) + "|");
+		}
+		BreadthFirstPath bfs = new BreadthFirstPath(graph, symbolGraphImpl.index("Bacon, Kevin"));
+		Iterable<Integer> pathTo = bfs.pathTo(symbolGraphImpl.index("Kidman, Nicole"));
+		System.out.println("Bacon, Kevin");
+		for(int w : pathTo){
+			System.out.println(symbolGraphImpl.name(w));
 		}
 	}
 }

Diff for: DataStructrue/Graph/UndirectedGraph.md

@@ -626,7 +626,7 @@ public class SymbolGraphImpl implements SymbolGraph {
 
 	@Override
 	public Graph G() { return G; }
-	
+
 	public static void main(String[] args) throws FileNotFoundException {
 		SymbolGraphImpl symbolGraphImpl = new SymbolGraphImpl("src/ca/mcmaster/chapter/four/graph/movies.txt", "/");
 		Graph graph = symbolGraphImpl.G();
@@ -639,4 +639,26 @@ public class SymbolGraphImpl implements SymbolGraph {
 		}
 	}
 }
+```
+
+#### 间隔的度数
+>间隔的度数实际上就是最短路径，即两个顶点之间的最短距离。
+```Java
+	public static void main(String[] args) throws FileNotFoundException {
+		SymbolGraphImpl symbolGraphImpl = new SymbolGraphImpl("src/ca/mcmaster/chapter/four/graph/movies.txt", "/");
+		Graph graph = symbolGraphImpl.G();
+		int vertexNum = graph.V();
+		for(int v = 0; v < vertexNum; v++){
+			StringBuilder sb = new StringBuilder(symbolGraphImpl.name(v) + " -> ");
+			for(int w : graph.adj(v))
+				sb.append(symbolGraphImpl.name(w) + "|");
+		}
+		//Use BFS to find the shorted path.
+		BreadthFirstPath bfs = new BreadthFirstPath(graph, symbolGraphImpl.index("Bacon, Kevin"));
+		Iterable<Integer> pathTo = bfs.pathTo(symbolGraphImpl.index("Kidman, Nicole"));
+		System.out.println("Bacon, Kevin");
+		for(int w : pathTo){
+			System.out.println(symbolGraphImpl.name(w));
+		}
+	}
 ```