链表，队列，堆栈中的练习

1，给定一个表L和另一个表P他们包含以升序排列的整数，操作在printLots（L，P）将打印L中那些有P所指位置上的元素。写出printLots（L，P）。

public static <AnyType> void printLots(List<AnyType> L,List <Integer> P){
Iterator<AnyType> iterL = L.iterator();
Iterator<Integer> iterP = P.iterator();
AnyType itemL=null;
Integer itemP=0;
int start = 0;
while ( iterL.hasNext() && iterP.hasNext() )
{
itemP = iterP.next();
System.out.println("Looking for position " + itemP);
while ( start < itemP && iterL.hasNext() )
{
start++;
itemL = iterL.next();
}
System.out.println( itemL );
}
}

2，通过只调整链表来交换两个相邻的元素，使用

a.单链表

b.双链表

(a) For singly linked lists:

public static void swapWithNext( Node beforep )
{
Node p, afterp;
p = beforep.next;
afterp = p.next; // Both p and afterp assumed not null.
p.next = afterp.next;
beforep.next = afterp;
afterp.next = p;
}

(b) For doubly linked lists:

public static void swapWithNext( Node p )
{
Node beforep, afterp;
beforep = p.prev;
afterp = p.next;
p.next = afterp.next;
beforep.next = afterp;
afterp.next = p;
p.next.prev = p;
p.prev = afterp;
afterp.prev = beforep;
}