题目链接 : https://leetcode-cn.com/problems/partition-list/
题目描述:
给定一个链表和一个特定值 x,对链表进行分隔,使得所有小于 x 的节点都在大于或等于 x 的节点之前。
你应当保留两个分区中每个节点的初始相对位置。
示例:
输入: head = 1->4->3->2->5->2, x = 3
输出: 1->2->2->4->3->5
思路:
用两个链表,一个链表放小于x
的节点,一个链表放大于等于x
的节点
最后,拼接这两个链表.
代码:
# Definition for singly-linked list.
# class ListNode:
# def __init__(self, x):
# self.val = x
# self.next = None
class Solution:
def partition(self, head: ListNode, x: int) -> ListNode:
dummy1 = ListNode(-1)
dummy2 = ListNode(-1)
p1 = dummy1
p2 = dummy2
while head:
if head.val < x:
p1.next = head
p1 = p1.next
else:
p2.next = head
p2 = p2.next
head = head.next
# print(listNodeToString(dummy1.next))
# print(listNodeToString(dummy2.next))
p1.next = dummy2.next
p2.next = None
return dummy1.next
java
/**
* Definition for singly-linked list.
* public class ListNode {
* int val;
* ListNode next;
* ListNode(int x) { val = x; }
* }
*/
class Solution {
public ListNode partition(ListNode head, int x) {
ListNode dummy1 = new ListNode(-1);
ListNode dummy2 = new ListNode(-1);
ListNode p1 = dummy1;
ListNode p2 = dummy2;
while (head != null) {
if (head.val < x) {
p1.next = head;
p1 = p1.next;
} else {
p2.next = head;
p2 = p2.next;
}
head = head.next;
}
p1.next = dummy2.next;
p2.next = null;
return dummy1.next;
}
}
原文地址:https://www.cnblogs.com/powercai/p/10994134.html
时间: 2024-10-09 00:57:56