[LeetCode] Partition List

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

.

class Solution {
public:
ListNode *partition(ListNode *head, int x) {
ListNode *cur = head;
ListNode *small = new ListNode(0);
ListNode *big = new ListNode(0);
ListNode *p = small;
ListNode *q = big;
while(cur){
if(cur -> val < x){
p -> next = cur;
cur = cur -> next;
p = p -> next;
p -> next = NULL;
}else{
q -> next = cur;
cur = cur -> next;
q = q -> next;
q -> next = NULL;
}
}
p -> next = big -> next;
return small -> next;
}
};