In this post, we are going to solve the Partition List Leetcode Solution problem of Leetcode. This Leetcode problem is done in many programming languages like C++, Java, and Python.
Problem
Given the head of 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.
Example 1:
Input: head = [1,4,3,2,5,2], x = 3 Output: [1,2,2,4,3,5]
Example 2:
Input: head = [2,1], x = 2 Output: [1,2]
Constraints:
- The number of nodes in the list is in the range
[0, 200]. -100 <= Node.val <= 100-200 <= x <= 200
Now, let’s see the leetcode solution of Partition List Leetcode Solution.
Partition List Leetcode Solution in Python
class Solution:
def partition(self, head: ListNode, x: int) -> ListNode:
beforeHead = ListNode(0)
afterHead = ListNode(0)
before = beforeHead
after = afterHead
while head:
if head.val < x:
before.next = head
before = head
else:
after.next = head
after = head
head = head.next
after.next = None
before.next = afterHead.next
return beforeHead.next
Partition List Leetcode Solution in CPP
class Solution {
public:
ListNode* partition(ListNode* head, int x) {
ListNode beforeHead(0);
ListNode afterHead(0);
ListNode* before = &beforeHead;
ListNode* after = &afterHead;
for (; head; head = head->next)
if (head->val < x) {
before->next = head;
before = head;
} else {
after->next = head;
after = head;
}
after->next = nullptr;
before->next = afterHead.next;
return beforeHead.next;
};
};
Partition List Leetcode Solution in Java
class Solution {
public ListNode partition(ListNode head, int x) {
ListNode beforeHead = new ListNode(0);
ListNode afterHead = new ListNode(0);
ListNode before = beforeHead;
ListNode after = afterHead;
for (; head != null; head = head.next)
if (head.val < x) {
before.next = head;
before = head;
} else {
after.next = head;
after = head;
}
after.next = null;
before.next = afterHead.next;
return beforeHead.next;
}
}
Note: This problem Partition List is generated by Leetcode but the solution is provided by Chase2learn This tutorial is only for Educational and Learning purposes.
