遍歷在Java

Question

循環鏈表對於show（）方法，我應該遍歷每個節點在循環鏈表，起始於第一，並且印刷是使用StdOut.println每個點（） 。

我能遍歷並打印出循環鏈表中的每個節點而不重複。我只是覺得有更好的方法來寫這個，但我不知道如何在while循環中包含第一個節點。如果我擺脫while循環上面的行，那麼最後一個節點不會被打印出來。把它放在while循環之上。有沒有辦法寫它，幷包含最後一個節點，而無需在while循環上方寫入行？

public class Tour { 
// Nested class Node to contain a Point and a reference 
// to the next Node in the tour 
private class Node { 
    Point p; 
    Node next; 
} 

private Node first; 
//private Node last; 
private int size; 
private double distance; 

// Create an empty Tour 
// Constructor that creates an empty tour 
public Tour() 
{ 
    first = null; 
    //last = null; 
    size = 0; 
    distance = 0.0; 
} 

// Create a 4 point tour a->b->c->d->a 
// Constructor that creates a 4 point tour and is 
// intended to assist with debugging 
public Tour(Point a, Point b, Point c, Point d) 
{ 
    Node one = new Node(); 
    Node two = new Node(); 
    Node three = new Node(); 
    Node four = new Node(); 

    one.p = a; 
    two.p = b; 
    three.p = c; 
    four.p = d; 

    one.next = two; 
    two.next = three; 
    three.next = four; 
    four.next = one; 

    first = one; 
    //last = four; 
} 

// Print the tour to standard output 
// Print constituent points to standard output 
public void show() 
{ 
    Node tmp = first; 

    if (tmp == null) 
    { 
     StdOut.println(""); 
     return; 
    } 

    StdOut.println(tmp.p.toString()); 
    while (tmp.next != first) 
    { 
     tmp = tmp.next; 
     StdOut.println(tmp.p.toString()); 
    } 
    return; 
} 

Answer 1

您可以使用一個do-while循環擺脫線的只是while循環之前：

Node tmp = first; 

if (tmp == null) 
{ 
    StdOut.println(""); 
    return; 
} 

do 
{ 
    StdOut.println(tmp.p.toString()); 
    tmp = tmp.next; 
} while (tmp != first); 

有沒有多少人可以做，以提高方法。

Answer 2

將其更改爲do-while循環。如果CLL爲空（即主節點爲空），則只需在內部包含一個if測試以防止發生NullPointerException。