一.题目及剖析

https://leetcode.cn/problems/partition-list-lcci/description/

二.思路引入

就是将其分成大小两个链表,以x为分界线进行分堆,最后再将两链表合并

三.代码引入

/*** Definition for singly-linked list.* struct ListNode {*     int val;*     struct ListNode *next;* };*/struct ListNode* partition(struct ListNode* head, int x){if(head == NULL)return head;struct ListNode *lessHead, *lessTail, *greaterHead, *greaterTail, *pcur;lessHead = lessTail = (struct ListNode*)malloc(sizeof(struct ListNode));greaterHead = greaterTail = (struct ListNode*)malloc(sizeof(struct ListNode));pcur = head;while(pcur){if(pcur->val < x){lessTail->next = pcur;lessTail = lessTail->next;}else{greaterTail->next = pcur;greaterTail = greaterTail->next;}pcur = pcur->next;}greaterTail->next = NULL;lessTail->next = greaterHead->next;return lessHead->next;
}