package algs44;
import stdlib.*;
/* ***********************************************************************
* Compilation: javac DirectedEdge.java
* Execution: java DirectedEdge
*
* Immutable weighted directed edge.
*
*************************************************************************/
/**
* The {@code DirectedEdge} class represents a weighted edge in an directed graph.
*
* For additional documentation, see Section 4.4 of
* Algorithms, 4th Edition by Robert Sedgewick and Kevin Wayne.
*/
public class DirectedEdge implements Comparable {
private final int v;
private final int w;
private final double weight;
/**
* Create a directed edge from v to w with given weight.
*/
public DirectedEdge(int v, int w, double weight) {
this.v = v;
this.w = w;
this.weight = weight;
}
/**
* Return the vertex where this edge begins.
*/
public int from() {
return v;
}
/**
* Return the vertex where this edge ends.
*/
public int to() {
return w;
}
/**
* Return the weight of this edge.
*/
public double weight() { return weight; }
/**
* Return a string representation of this edge.
*/
public String toString() {
return String.format("%d->%d %.2f", v, w, weight);
}
/**
* Compare by weights.
*/
public int compareTo (DirectedEdge o) {
if (weight < o.weight) return -1;
if (weight > o.weight) return 1;
return 0;
}
/**
* Test client.
*/
public static void main(String[] args) {
DirectedEdge e = new DirectedEdge(12, 23, 3.14);
StdOut.println(e);
}
}