Question Definition
Given a linked list and a value x, partition it such that all nodes less than x come before nodes greater than or equal to x.
You should preserve the original relative order of the nodes in each of the two partitions.
For example,
Given 1->4->3->2->5->2 and x = 3,
return 1->2->2->4->3->5.
Java Solution
public ListNode partition(ListNode head, int x) {
if(head == null) return head;
ListNode dummy = new ListNode(-1);
ListNode newDummy = new ListNode(-1);
dummy.next = head;
ListNode cur = dummy, p = newDummy;
while (cur.next != null) {
if (cur.next.val < x) {
p.next = cur.next;
p = p.next;
cur.next = cur.next.next;
p.next = null;
} else {
cur = cur.next;
}
}
p.next = dummy.next;
return newDummy.next;
}
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