[LeetCode]Insertion Sort List

class Solution {
public:
ListNode *insertionSortList(ListNode *head) {
ListNode *q = head;
ListNode *temp = new ListNode(0);
temp->val = INT_MIN;
temp->next = NULL;
ListNode *p = temp;
ListNode * pre = NULL;
ListNode *k = NULL;
ListNode *f = NULL;
while (q != NULL) {
f = q;
q = q->next;
k = temp;
while(1) {
if (k == NULL) {
f->next = NULL;
pre->next = f;
break;
}
if (f->val < k->val) {
f->next = pre->next;
pre->next = f;
pre = k;
break;
}
pre = k;
k = k->next;
}
pre = NULL;
}
p = temp->next;
temp->next = NULL;
delete temp;
return p;
}
};