tidy whitespace

1 files changed, 381 insertions, 320 deletions

diff --git a/src/com.example.portfolio3/com/example/portfolio3/GraphAlgorithms.java b/src/com.example.portfolio3/com/example/portfolio3/GraphAlgorithms.java
index d2a20f2..6b47bd2 100644
--- a/src/com.example.portfolio3/com/example/portfolio3/GraphAlgorithms.java
+++ b/src/com.example.portfolio3/com/example/portfolio3/GraphAlgorithms.java
@@ -19,324 +19,385 @@ import java.util.Set;
 /// foo
 public class GraphAlgorithms {
 
-  /// foo
-  GraphAlgorithms() {}
-
-  /// Calculates the length of a path or any other collection of edes
-  ///
-  /// does not require the edges to form a path
-  /// @param edges  foo
-  /// @return int
-  public static int pathLength(final Collection<Edge> edges){
-    return edges.stream().mapToInt(e-> e.weight()).sum();
-  }
-
-  /// checks whether a list of edges form a path so that
-  ///
-  /// the to-vertex in one edge is the from-vertex of the next
-  /// @param edges  foo
-  /// @return boolean
-  public static boolean isPath(final List<Edge> edges){
-    for(int i=1;i<edges.size();i++){
-      if(edges.get(i-1).to()!=edges.get(i).from())return false;
-    }
-    return true;
-  }
-
-  ///Calculates the length of a path vertices in a graph
-  ///
-  /// return null if vertices are not connected as a path
-  /// @param g     foo
-  /// @param path  foo
-  /// @return Integer
-  public static Integer pathLength(final Graph g, final List<Vertex> path){
-    int length=0;
-    for(int i=1;i<path.size();i++){
-      Integer w=g.getWeight(path.get(i-1),path.get(i));
-      if(w==null)return null;
-      length+=w;
-    }
-    return length;
-  }
-
-  //------------------------------------------------------------
-  //
-  //  Comparators and sorting methods
-
-  /// Comparator of edges based on weight
-  ///
-  /// can be used for sorting a list of edges
-  /// @param e1  foo
-  /// @param e2  foo
-  /// @return int
-  static int cmpEdgeWeight(final Edge e1, final Edge e2) {
-    int w1=e1.weight(),w2=e2.weight();
-    if(w1!=w2)return w1-w2;
-    if(e1.from()!=e2.from())return e1.from().name().compareTo(e2.from().name());
-    return e1.to().name().compareTo(e2.to().name());
-  }
-
-  /// Comparator of edges based on from-vertex
-  ///
-  /// can be used for sorting a list of edges
-  /// @param e1  foo
-  /// @param e2  foo
-  /// @return int
-  static int cmpEdgeFrom(final Edge e1, final Edge e2) {
-    if(e1.from()!=e2.from())return e1.from().name().compareTo(e2.from().name());
-    int w1=e1.weight(),w2=e2.weight();
-    if(w1!=w2)return w1-w2;
-    return e1.to().name().compareTo(e2.to().name());
-  }
-
-  /// Comparator of edges based on from-vertex
-  ///
-  /// can be used for sorting a list of edges
-  /// @param e1  foo
-  /// @param e2  foo
-  /// @return int
-  static int cmpEdgeTo(final Edge e1, final Edge e2) {
-    if(e1.to()!=e2.to())return e1.to().name().compareTo(e2.to().name());
-    if(e1.from()!=e2.from())return e1.from().name().compareTo(e2.from().name());
-    int w1=e1.weight(),w2=e2.weight();
-    return w1-w2;
-  }
-
-  /// sort a collection of edges based on their weights
-  /// @param edges  foo
-  /// @return List<Edge>
-  static List<Edge> sortEdges(final Collection<Edge> edges){
-    ArrayList<Edge> list=new ArrayList<>(edges);
-    Collections.sort(list,GraphAlgorithms::cmpEdgeWeight);
-    return list;
-  }
-
-  /// sort a collection of edges based on from-vertex
-  /// @param edges  foo
-  /// @return List<Edge>
-  static List<Edge> sortEdgesFrom(final Collection<Edge> edges){
-    ArrayList<Edge> list=new ArrayList<>(edges);
-    Collections.sort(list,GraphAlgorithms::cmpEdgeFrom);
-    return list;
-  }
-
-  /// sort a collection of edges based on to-vertex
-  /// @param edges  foo
-  /// @return List<Edge>
-  static List<Edge> sortEdgesTo(final Collection<Edge> edges){
-    ArrayList<Edge> list=new ArrayList<>(edges);
-    Collections.sort(list,GraphAlgorithms::cmpEdgeTo);
-    return list;
-  }
-
-  /// sort a collection of vertices based on their name
-  /// @param vertices  foo
-  /// @return List<Vertex>
-  public static List<Vertex> sortVertex(final Collection<Vertex> vertices){
-    ArrayList<Vertex> list=new ArrayList<>(vertices);
-    Collections.sort(list,(Vertex v1,Vertex v2)-> v1.name().compareTo(v2.name()));
-    return list;
-  }
-
-  //------------------------------------------------------------
-  //
-  //  Algorithms for traverse and minimum spanning tree
-
-  /// traverse a graph depth first from a given vertex
-  /// return the set of visited vertices
-  /// @param g  foo
-  /// @param v  foo
-  /// @return Set<Vertex>
-  public static Set<Vertex> visitBreadthFirst(final Graph g, final Vertex v){
-    HashSet<Vertex> thisLevel=new HashSet<>();
-    HashSet<Vertex> nextLevel=new HashSet<>();
-    HashSet<Vertex> visited=new HashSet<>();
-    thisLevel.add(v);
-    while(thisLevel.size()>0){
-      System.out.println("level "+thisLevel);
-      for(Vertex w:thisLevel){
-        //System.out.println("visited "+w);
-        visited.add(w);
-        Collection<Edge> outedge=g.outEdge(w);
-        if(outedge==null)continue;
-        for(Edge e: outedge){
-          if(visited.contains(e.to()))continue;
-          if(thisLevel.contains(e.to()))continue;
-          nextLevel.add(e.to());
-        }
-      }
-      thisLevel=nextLevel;
-      nextLevel=new HashSet<Vertex>();
-    }
-    return visited;
-  }
-
-  /// traverse a graph depth first from a given vertex
-  /// return the set of visited vertices
-  /// @param g  foo
-  /// @param v  foo
-  /// @return Set<Vertex>
-  public static Set<Vertex> visitDepthFirst(final Graph g, final Vertex v){
-    HashSet<Vertex> visit=new HashSet<>();
-    visitDepthFirst(g, v,visit);
-    return visit;
-  }
-
-  /// foo
-  /// @param g        foo
-  /// @param v        foo
-  /// @param visited  foo
-  private static void visitDepthFirst(final Graph g, final Vertex v, final Set<Vertex> visited){
-    if(visited.contains(v))return;
-    //System.out.println("visited "+v);
-    visited.add(v);
-    for(Edge e: g.outEdge(v))
-      visitDepthFirst(g,e.to(),visited);
-  }
-
-  /// an implementation of Prim's algorithm
-  /// naive implementation without priorityqueue
-  /// @param g  foo
-  /// @return Set<Edge>
-  public static Set<Edge> minimumSpanningTree(final Graph g){
-    Collection<Edge> edges=g.edges();
-    HashSet<Edge> mst=new HashSet<>();
-    HashSet<Vertex> frontier=new HashSet<>();
-    for(Edge e:edges){frontier.add(e.from());break;}
-    while(true) {
-      Edge nearest = null;
-      for (Edge e : edges) {
-        if (!frontier.contains(e.from())) continue;
-        if (frontier.contains(e.to())) continue;
-        if (nearest == null || nearest.weight() > e.weight())
-          nearest = e;
-      }
-      if(nearest==null)break;
-      mst.add(nearest);
-      frontier.add(nearest.to());
-    }
-    return mst;
-  }
-
-  /// returns the tree of shortest paths from start to
-  /// all vertices  in the graph
-  ///
-  /// naive implementation without a prorityqueue
-  /// @param g      foo
-  /// @param start  foo
-  /// @return Set<Edge>
-  public static Set<Edge> dijkstra(final Graph g, final Vertex start){
-    // create table for done, prev and weight from start
-    int maxint =Integer.MAX_VALUE;
-    HashSet<Vertex> done=new HashSet<>();
-    HashMap<Vertex,Edge> prev=new HashMap<>();
-    HashMap<Vertex,Integer> weight=new HashMap<>();
-    for(Vertex w:g.vertices())weight.put(w,maxint);
-    // start node is done, distance 0 from start
-    weight.put(start,0);
-    done.add(start);
-
-    while(true){
-      // find nearest from a done vertex
-      Vertex nearest = null;
-      int neardist = maxint;
-      Edge done2near=null;
-      for(Vertex w1:done){
-        for (Edge e : g.outEdge(w1)) {
-          Vertex w2 = e.to();
-          if (done.contains(w2)) continue;
-          if ((weight.get(w1) + e.weight()) < neardist) {
-            nearest = e.to();
-            neardist = weight.get(w1) + e.weight();
-            done2near = e;
-          }
-        }
-      }
-      // System.out.println("find nearest "+done2near);
-      // if no more, then we are done
-      if (nearest == null) break;
-        // update distance from this node to other nodes
-      for (Edge e1 : g.outEdge(nearest)) {
-        Vertex w3 = e1.to();
-        int wght = e1.weight();
-        if (weight.get(w3) > (neardist + wght)) {
-          weight.put(w3, neardist + wght);
-        }
-      }
-      done.add(nearest);
-      prev.put(nearest,done2near);
-      weight.put(nearest,neardist);
-    }
-    return new HashSet<Edge>(prev.values());
-  }
-
-  //------------------------------------------------------------
-  //
-  //  IO operations
-
-  /// read a comma-separated file in the format
-  /// <vertex> , <vertex> , <weight>
-  ///
-  /// stores file as bidirectional graph
-  /// @param g     foo
-  /// @param file  foo
-  public static void readGraph(final Graph g, final String file) {
-    try{
-      BufferedReader in = new BufferedReader(new FileReader(file));
-      for(String line=in.readLine(); line!=null; line=in.readLine()) {
-        if(line.length()==0) continue;
-        String[] arr = line.split(",");
-        if(arr.length!=3) throw new RuntimeException("CSV file format error: "+line);
-        g.insertEdge(arr[0].trim(), arr[1].trim(), Integer.parseInt(arr[2].trim()));
-        g.insertEdge(arr[1].trim(), arr[0].trim(), Integer.parseInt(arr[2].trim()));
-      }
-      in.close();
-    }catch(IOException e){
-      throw new RuntimeException(e);
-    }
-  }
-
-  /// foo
-  /// @param g  foo
-  public static void printGraph(final Graph g) {
-    for(Vertex v: sortVertex(g.vertices())) {
-      System.out.println(v.toString());
-      for(Edge e:sortEdgesTo(g.outEdge(v)))
-        System.out.println("  "+e.toString());
-    }
-  }
-
-  /// store a list of lines as a file
-  /// @param list  foo
-  /// @param f     foo
-  public static void storeStrings(final List<String> list, final String f){
-    try{
-      PrintWriter out=new PrintWriter(new FileWriter(f));
-      for(String s:list){
-        out.println(s);
-      }
-      out.close();
-    }catch(IOException e){
-      throw new RuntimeException(e);
-    }
-  }
-
-  /// read a file a returns a list of lines
-  /// @param f  foo
-  /// @return ArrayList
-  public static ArrayList<String> loadStrings(final String f){
-    ArrayList<String> list=new ArrayList<>();
-    try{
-      BufferedReader in=new BufferedReader(new FileReader(f));
-      while(true){
-        String s=in.readLine();
-        if(s==null)break;
-        list.add(s);
-      }
-      in.close();
-    }catch(IOException e){
-      throw new RuntimeException(e);
-    }
-    return list;
-  }
+	/// foo
+	GraphAlgorithms() { }
+
+	/// Calculates the length of a path or any other collection of edes
+	///
+	/// does not require the edges to form a path
+	///
+	/// @param edges  foo
+	/// @return int
+	public static int pathLength(final Collection<Edge> edges) {
+		return edges.stream().mapToInt(e -> e.weight()).sum();
+	}
+
+	/// checks whether a list of edges form a path so that
+	///
+	/// the to-vertex in one edge is the from-vertex of the next
+	///
+	/// @param edges  foo
+	/// @return       boolean
+	public static boolean isPath(final List<Edge> edges) {
+		for (int i = 1; i < edges.size(); i++) {
+			if (edges.get(i - 1).to() != edges.get(i).from())
+				return false;
+		}
+
+		return true;
+	}
+
+	/// Calculates the length of a path vertices in a graph
+	///
+	/// return null if vertices are not connected as a path
+	///
+	/// @param g     foo
+	/// @param path  foo
+	/// @return      Integer
+	public static Integer pathLength(final Graph g, final List<Vertex> path) {
+		int length = 0;
+		for (int i = 1; i < path.size(); i++) {
+			Integer w = g.getWeight(path.get(i - 1),path.get(i));
+			if (w == null)
+				return null;
+			length += w;
+		}
+
+		return length;
+	}
+
+	//------------------------------------------------------------
+	//
+	// Comparators and sorting methods
+
+	/// Comparator of edges based on weight
+	///
+	/// can be used for sorting a list of edges
+	///
+	/// @param e1  foo
+	/// @param e2  foo
+	/// @return    int
+	static int cmpEdgeWeight(final Edge e1, final Edge e2) {
+		int w1 = e1.weight(), w2 = e2.weight();
+		if (w1 != w2)
+			return w1 - w2;
+		if (e1.from() != e2.from())
+			return e1.from().name().compareTo(e2.from().name());
+
+		return e1.to().name().compareTo(e2.to().name());
+	}
+
+	/// Comparator of edges based on from-vertex
+	///
+	/// can be used for sorting a list of edges
+	///
+	/// @param e1  foo
+	/// @param e2  foo
+	/// @return    int
+	static int cmpEdgeFrom(final Edge e1, final Edge e2) {
+		if (e1.from() != e2.from())
+			return e1.from().name().compareTo(e2.from().name());
+		int w1 = e1.weight(), w2 = e2.weight();
+		if (w1 != w2)
+			return w1 - w2;
+
+		return e1.to().name().compareTo(e2.to().name());
+	}
+
+	/// Comparator of edges based on from-vertex
+	///
+	/// can be used for sorting a list of edges
+	///
+	/// @param e1  foo
+	/// @param e2  foo
+	/// @return    int
+	static int cmpEdgeTo(final Edge e1, final Edge e2) {
+		if (e1.to() != e2.to())
+			return e1.to().name().compareTo(e2.to().name());
+		if (e1.from() != e2.from())
+			return e1.from().name().compareTo(e2.from().name());
+		int w1 = e1.weight(), w2 = e2.weight();
+
+		return w1 - w2;
+	}
+
+	/// sort a collection of edges based on their weights
+	///
+	/// @param edges  foo
+	/// @return       List<Edge>
+	static List<Edge> sortEdges(final Collection<Edge> edges) {
+		ArrayList<Edge> list = new ArrayList<>(edges);
+		Collections.sort(list, GraphAlgorithms::cmpEdgeWeight);
+
+		return list;
+	}
+
+	/// sort a collection of edges based on from-vertex
+	///
+	/// @param edges  foo
+	/// @return       List<Edge>
+	static List<Edge> sortEdgesFrom(final Collection<Edge> edges) {
+		ArrayList<Edge> list = new ArrayList<>(edges);
+		Collections.sort(list, GraphAlgorithms::cmpEdgeFrom);
+
+		return list;
+	}
+
+	/// sort a collection of edges based on to-vertex
+	///
+	/// @param edges  foo
+	/// @return       List<Edge>
+	static List<Edge> sortEdgesTo(final Collection<Edge> edges) {
+		ArrayList<Edge> list = new ArrayList<>(edges);
+		Collections.sort(list, GraphAlgorithms::cmpEdgeTo);
+
+		return list;
+	}
+
+	/// sort a collection of vertices based on their name
+	///
+	/// @param vertices  foo
+	/// @return          List<Vertex>
+	public static List<Vertex> sortVertex(final Collection<Vertex> vertices) {
+		ArrayList<Vertex> list = new ArrayList<>(vertices);
+		Collections.sort(list, (Vertex v1, Vertex v2) -> v1.name().compareTo(v2.name()));
+
+		return list;
+	}
+
+	//------------------------------------------------------------
+	//
+	// Algorithms for traverse and minimum spanning tree
+
+	/// traverse a graph depth first from a given vertex
+	/// return the set of visited vertices
+	///
+	/// @param g  foo
+	/// @param v  foo
+	/// @return   Set<Vertex>
+	public static Set<Vertex> visitBreadthFirst(final Graph g, final Vertex v) {
+		HashSet<Vertex> thisLevel = new HashSet<>();
+		HashSet<Vertex> nextLevel = new HashSet<>();
+		HashSet<Vertex> visited = new HashSet<>();
+		thisLevel.add(v);
+		while (thisLevel.size() > 0) {
+			System.out.println("level " + thisLevel);
+			for (Vertex w:thisLevel) {
+				//System.out.println("visited " + w);
+				visited.add(w);
+				Collection<Edge> outedge = g.outEdge(w);
+				if (outedge == null)
+					continue;
+				for (Edge e: outedge) {
+					if (visited.contains(e.to()))
+						continue;
+					if (thisLevel.contains(e.to()))
+						continue;
+					nextLevel.add(e.to());
+				}
+			}
+			thisLevel = nextLevel;
+			nextLevel = new HashSet<Vertex>();
+		}
+
+		return visited;
+	}
+
+	/// traverse a graph depth first from a given vertex
+	/// return the set of visited vertices
+	///
+	/// @param g  foo
+	/// @param v  foo
+	/// @return   Set<Vertex>
+	public static Set<Vertex> visitDepthFirst(final Graph g, final Vertex v) {
+		HashSet<Vertex> visit = new HashSet<>();
+		visitDepthFirst(g, v, visit);
+
+		return visit;
+	}
+
+	/// foo
+	///
+	/// @param g        foo
+	/// @param v        foo
+	/// @param visited  foo
+	private static void visitDepthFirst(final Graph g, final Vertex v, final Set<Vertex> visited) {
+		if (visited.contains(v))
+			return;
+		//System.out.println("visited "+v);
+		visited.add(v);
+		for (Edge e: g.outEdge(v))
+			visitDepthFirst(g, e.to(), visited);
+	}
+
+	/// an implementation of Prim's algorithm
+	///
+	/// naive implementation without priorityqueue
+	///
+	/// @param g  foo
+	/// @return   Set<Edge>
+	public static Set<Edge> minimumSpanningTree(final Graph g) {
+		Collection<Edge> edges = g.edges();
+		HashSet<Edge> mst = new HashSet<>();
+		HashSet<Vertex> frontier = new HashSet<>();
+		for (Edge e:edges) {
+			frontier.add(e.from());
+			break;
+		}
+		while (true) {
+			Edge nearest = null;
+			for (Edge e: edges) {
+				if (!frontier.contains(e.from()))
+					continue;
+				if (frontier.contains(e.to()))
+					continue;
+				if (nearest == null || nearest.weight() > e.weight())
+					nearest = e;
+			}
+			if (nearest == null)
+				break;
+			mst.add(nearest);
+			frontier.add(nearest.to());
+		}
+
+		return mst;
+	}
+
+	/// returns the tree of shortest paths
+	/// from start to all vertices in the graph
+	///
+	/// naive implementation without a prorityqueue
+	///
+	/// @param g      foo
+	/// @param start  foo
+	/// @return       Set<Edge>
+	public static Set<Edge> dijkstra(final Graph g, final Vertex start) {
+
+		// create table for done, prev and weight from start
+		int maxint = Integer.MAX_VALUE;
+		HashSet<Vertex> done = new HashSet<>();
+		HashMap<Vertex,Edge> prev = new HashMap<>();
+		HashMap<Vertex,Integer> weight = new HashMap<>();
+		for (Vertex w: g.vertices())
+			weight.put(w, maxint);
+
+		// start node is done, distance 0 from start
+		weight.put(start, 0);
+		done.add(start);
+
+		while (true) {
+
+			// find nearest from a done vertex
+			Vertex nearest = null;
+			int neardist = maxint;
+			Edge done2near = null;
+			for (Vertex w1:done) {
+				for (Edge e :g.outEdge(w1)) {
+					Vertex w2 = e.to();
+					if (done.contains(w2)) continue;
+					if ((weight.get(w1) + e.weight()) < neardist) {
+						nearest = e.to();
+						neardist = weight.get(w1) + e.weight();
+						done2near = e;
+					}
+				}
+			}
+
+			// System.out.println("find nearest "+done2near);
+			// if no more, then we are done
+			if (nearest == null) break;
+
+			// update distance from this node to other nodes
+			for (Edge e1 : g.outEdge(nearest)) {
+				Vertex w3 = e1.to();
+				int wght = e1.weight();
+				if (weight.get(w3) > (neardist + wght)) {
+					weight.put(w3, neardist + wght);
+				}
+			}
+			done.add(nearest);
+			prev.put(nearest,done2near);
+			weight.put(nearest,neardist);
+		}
+
+		return new HashSet<Edge>(prev.values());
+	}
+
+	//------------------------------------------------------------
+	//
+	// IO operations
+
+	/// read a comma-separated file
+	/// in the format <vertex> , <vertex> , <weight>
+	///
+	/// stores file as bidirectional graph
+	///
+	/// @param g     foo
+	/// @param file  foo
+	public static void readGraph(final Graph g, final String file) {
+		try {
+			BufferedReader in = new BufferedReader(new FileReader(file));
+			for (String line = in.readLine(); line != null; line = in.readLine()) {
+				if (line.length() == 0)
+					continue;
+				String[] arr = line.split(",");
+				if (arr.length != 3)
+					throw new RuntimeException("CSV file format error: " + line);
+				g.insertEdge(arr[0].trim(), arr[1].trim(), Integer.parseInt(arr[2].trim()));
+				g.insertEdge(arr[1].trim(), arr[0].trim(), Integer.parseInt(arr[2].trim()));
+			}
+			in.close();
+		} catch (IOException e) {
+			throw new RuntimeException(e);
+		}
+	}
+
+	/// foo
+	///
+	/// @param g  foo
+	public static void printGraph(final Graph g) {
+		for (Vertex v: sortVertex(g.vertices())) {
+			System.out.println(v.toString());
+			for (Edge e: sortEdgesTo(g.outEdge(v)))
+				System.out.println("  " + e.toString());
+		}
+	}
+
+	/// store a list of lines as a file
+	///
+	/// @param list  foo
+	/// @param f     foo
+	public static void storeStrings(final List<String> list, final String f) {
+		try {
+			PrintWriter out = new PrintWriter(new FileWriter(f));
+			for (String s: list) {
+				out.println(s);
+			}
+			out.close();
+		} catch (IOException e) {
+			throw new RuntimeException(e);
+		}
+	}
+
+	/// read a file a returns a list of lines
+	///
+	/// @param f  foo
+	/// @return   ArrayList
+	public static ArrayList<String> loadStrings(final String f) {
+		ArrayList<String> list = new ArrayList<>();
+		try {
+			BufferedReader in = new BufferedReader(new FileReader(f));
+			while (true) {
+				String s = in.readLine();
+				if (s == null)
+					break;
+				list.add(s);
+			}
+			in.close();
+		} catch (IOException e) {
+			throw new RuntimeException(e);
+		}
+
+		return list;
+	}
 }