DepthFirstPaths (Algorithms 4/e)

Object
- edu.princeton.cs.algs4.DepthFirstPaths

```
public class DepthFirstPaths
extends Object
```
The DepthFirstPaths class represents a data type for finding paths from a source vertex s to every other vertex in an undirected graph.
This implementation uses depth-first search. The constructor takes Θ(V + E) time in the worst case, where V is the number of vertices and E is the number of edges. Each instance method takes Θ(1) time. It uses Θ(V) extra space (not including the graph).
For additional documentation, see Section 4.1 of Algorithms, 4th Edition by Robert Sedgewick and Kevin Wayne.

Author:

Robert Sedgewick, Kevin Wayne

Constructor Summary

Constructors
Constructor Description

DepthFirstPaths(Graph graph, int s)
Computes a path between s and every other vertex in graph.

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`boolean`	`hasPathTo(int v)`	Is there a path between the source vertex `s` and vertex `v`?
`static void`	`main(String[] args)`	Unit tests the `DepthFirstPaths` data type.
`Iterable<Integer>`	`pathTo(int v)`	Returns a path between the source vertex `s` and vertex `v`, or `null` if no such path.

Methods inherited from class java.lang.Object
clone, equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - DepthFirstPaths
```
public DepthFirstPaths(Graph graph,
                       int s)
```
    Computes a path between s and every other vertex in graph.
    
    Parameters:
    
    graph - the graph
    
    s - the source vertex
    
    Throws:
    
    IllegalArgumentException - unless 0 <= s < V
- Method Detail
  - hasPathTo
```
public boolean hasPathTo(int v)
```
    Is there a path between the source vertex s and vertex v?
    
    Parameters:
    
    v - the vertex
    
    Returns:
    
    true if there is a path, false otherwise
    
    Throws:
    
    IllegalArgumentException - unless 0 <= v < V
  - pathTo
```
public Iterable<Integer> pathTo(int v)
```
    Returns a path between the source vertex s and vertex v, or null if no such path.
    
    Parameters:
    
    v - the vertex
    
    Returns:
    
    the sequence of vertices on a path between the source vertex s and vertex v, as an Iterable
    
    Throws:
    
    IllegalArgumentException - unless 0 <= v < V
  - main
```
public static void main(String[] args)
```
    Unit tests the DepthFirstPaths data type.
    
    Parameters:
    
    args - the command-line arguments