/*** Definition for singly-linked list.* struct ListNode {*     int val;*     struct ListNode *next;* };*/
struct ListNode* partition(struct ListNode* head, int x) {struct ListNode* small=malloc(sizeof(struct ListNode));struct ListNode* smallHead=small;struct ListNode* large=malloc(sizeof(struct ListNode));struct ListNode* largeHead=large;while(head!=NULL){if(head->val<x){small->next=head;small=small->next;}else{large->next=head;large=large->next;}head=head->next;}large->next=NULL;small->next=largeHead->next;return smallHead->next;
}