alg4 directed graph

Author: gdhucoder

Ch_4_4/Ex_4_4_01.java

@@ -1,41 +1,34 @@
 package Ch_4_4;
 
-import edu.princeton.cs.algs4.StdOut;
-
 /**
- * Created by HuGuodong on 2018/12/30.
+ * Created by HuGuodong on 5/12/20.
  */
-
 public class _DirectedEdge {
 
   private final int v;
   private final int w;
   private final double weight;
 
-  public _DirectedEdge(int v, int w, double weight){
+  public _DirectedEdge(int v, int w, double weight) {
     this.v = v;
     this.w = w;
     this.weight = weight;
   }
 
-  public double weight(){
-    return weight;
-  }
-
-  public int from(){
-    return v;
+  public double weight() {
+    return this.weight;
   }
 
-  public int to(){
-    return w;
+  public int from() {
+    return this.v;
   }
 
-  public String toString(){
-    return String.format("%d->%d %5.2f", v, w, weight);
+  public int to() {
+    return this.w;
   }
 
-  public static void main(String[] args) {
-    _DirectedEdge e = new _DirectedEdge(5,10, 2.22);
-    StdOut.println(e);
+  @Override
+  public String toString() {
+    return String.format("%d->%d %.2f", v, w, weight);
   }
 }

Ch_4_4/_AcyclicSP.java

@@ -1,87 +1,39 @@
 package Ch_4_4;
 
-import Ch_4_3._Edge;
 import edu.princeton.cs.algs4.Bag;
-import edu.princeton.cs.algs4.In;
-import edu.princeton.cs.algs4.StdOut;
 
 /**
- * Created by HuGuodong on 2018/12/30.
+ * Created by HuGuodong on 5/12/20.
  */
-
 public class _EdgeWeightedDigraph {
 
   private final int V;
   private int E;
   private Bag<_DirectedEdge>[] adj;
 
-  private static final String NEWLINE = System.getProperty("line.separator");
-
-  public _EdgeWeightedDigraph(int V){
+  public _EdgeWeightedDigraph(int V) {
     this.V = V;
     this.E = 0;
-    adj = (Bag<_DirectedEdge>[]) new Bag[V];
+    adj = new Bag[V];
     for (int v = 0; v < V; v++) {
       adj[v] = new Bag<>();
     }
   }
 
-  public _EdgeWeightedDigraph(In in){
-    this(in.readInt());
-    int E = in.readInt();
-    for (int i = 0; i < E; i++) {
-      int v = in.readInt();
-      int w = in.readInt();
-      double weight = in.readDouble();
-      _DirectedEdge edge = new _DirectedEdge(v, w, weight);
-      addEdge(edge);
-    }
-  }
-
-  public int V(){
-    return V;
+  public int V() {
+    return this.V;
   }
 
-  public int E(){
-    return E;
+  public int E() {
+    return this.E;
   }
 
-  public void addEdge(_DirectedEdge e){
+  public void addEdge(_DirectedEdge e) {
     adj[e.from()].add(e);
     E++;
   }
 
-  public Iterable<_DirectedEdge> adj(int v){
+  public Iterable<_DirectedEdge> adj(int v) {
     return adj[v];
   }
-
-  public Iterable<_DirectedEdge> edges(){
-    Bag<_DirectedEdge> bag = new Bag<>();
-    for (int v = 0; v < V; v++) {
-      for(_DirectedEdge e : adj[v]){
-        bag.add(e);
-      }
-    }
-    return bag;
-  }
-
-  @Override
-  public String toString() {
-    StringBuilder s = new StringBuilder();
-    s.append(V + " " + E + NEWLINE);
-    for (int v = 0; v < V; v++) {
-      s.append(v + ": ");
-      for (_DirectedEdge e : adj[v]) {
-        s.append(e + ", ");
-      }
-      s.setLength(s.length()-2); // 删除最后的空格
-      s.append(NEWLINE);
-    }
-    return s.toString();
-  }
-
-  public static void main(String[] args) {
-    _EdgeWeightedDigraph g = new _EdgeWeightedDigraph(new In("tinyEWD.txt"));
-    StdOut.println(g);
-  }
 }