Offer-js-List of swords and fingers

(1) Enter a list to print the value of each node of the list from the end of the head.

Idea: Using an array to receive the printed list, the structure of the list is given.

/*function ListNode (x) {

This.val = x;

This.next = null;

}*/

function Printlistfromtailtohead (head)

{

var arr=[];

while (head) {

Arr.unshift (Head.val);

Head=head.next;

}

return arr;

}

(2)

Enter a list to output the last K nodes in the linked list .

Function Findkthtotail (head, K)

{

var arr=[];

while (head)

{

Arr.push (head);

Head=head.next;

}

if (arr.length==0 | | k>arr.length) {return false;}

return arr[arr.length-k];

}

(3) Enter a list of all the elements of the linked list after the list is inverted.

Idea: Create a new head node, traverse the original list, and insert each node into the new linked list with a head node. Finally, the newly created linked list is the inverted list.

function Reverselist (phead)

{

var pre = null;

var next = null;

while (Phead) {

Next = Phead.next;

Phead.next = pre;

Pre = Phead;

Phead = Next;

}

return pre;

}

(4) Input two monotonically increasing list, output two linked list of the linked list, of course, we need to synthesize the linked list to meet the monotone non-reduction rules.

function Merge (pHead1, pHead2)
{
if (PHead1 = = NULL | | pHead2 = = NULL) {
return PHead1 | | PHead2;
}

var head = null;

if (Phead1.val < Phead2.val) {
head = PHead1;
Head.next = Merge (Phead2,phead1.next)
}
else {
head = pHead2;
Head.next = Merge (PHead1, Phead2.next);
}
return head;

}

(5) Enter a complex list (node value in each node, and two pointers, one point to the next node, another special pointer to any node), and the result is the head of the complex linked list after replication.

递归思想：把大问题转化若干子问题 此题转化为一个头结点和除去头结点剩余部分，剩余部分操作和原问题一致


function Randomlistnode (x) {
This.label = x;
This.next = null;
This.random = null;
}
function Clone (phead)
{
if (!phead) {
return null;
}
var clonehead=new randomlistnode (Phead.label);
Clonehead.label=phead.label;
Clonehead.random=phead.random;

Clonehead.next=clone (Phead.next);
return clonehead;
}

Offer-js-List of swords and fingers