double findMedianSortedArrays(int* nums1, int l1, int* nums2, int l2)
{
if (!l1 && !l2) return 0.0;
int m1, m2;
int *p1, *p2;
m1 = (l1 + l2 - 1) / 2;
m2 = m1;
if ((l1 + l2) % 2 == 0)
m2 += 1;
p1 = findmid(nums1, l1, nums2, l2, m1);
if (!p1)
p1 = findmid(nums2, l2, nums1, l1, m1);
p2 = findmid(nums1, l1, nums2, l2, m2);
if (!p2)
p2 = findmid(nums2, l2, nums1, l1, m2);
return 1.0 * (*p1 + *p2) / 2;
}
ListNode *sortList(ListNode *head) {
if (head == NULL || head -> next == NULL) {
return head;
}
ListNode *mid = findmid(head);
ListNode *right = sortList(mid -> next);
mid -> next = NULL;
ListNode *left = sortList(head);
return sortList_merge(left, right);
}