PROBLEM DESCRIPTION
A linked list of length n is given such that each node contains an additional random pointer, which could point to any node in the list, or null. Construct a deep copy of the list.
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class Node {
int val;
Node next;
Node random;
public Node(int val) {
this.val = val;
this.next = null;
this.random = null;
}
}
SOLUTION
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class Solution {
public Node copyRandomList(Node head) {
if(head == null) return null;
Node t = head;
while(t != null){
Node newNode = new Node(t.val);
newNode.next = t.next;
t.next=newNode;
t=t.next.next;
}
t = head;
while(t != null){
Node r = t.random;
if(r == null){
t = t.next.next;
continue;
}
t.next.random = r.next;
t = t.next.next;
}
Node h2=head.next;
Node t1 = head;
Node t2 = head.next;
while(t2 != null){
t1.next = t2.next;
t1 = t1.next;
if(t1==null)break;
t2.next = t1.next;
t2 = t2.next;
}
return h2;
}
}