TheAlgorithms-C/leetcode/src/109.c

struct TreeNode* buildBST(struct ListNode* head, struct ListNode* tail) {
    if(head == tail)
        return NULL;
    struct ListNode* slow = head, *fast = head;
    while(fast != tail && fast->next != tail) {
        fast = fast->next->next;
        slow = slow->next;
    }
    struct TreeNode* node = malloc(sizeof(struct TreeNode));
    node->val = slow->val;
    node->left = buildBST(head, slow);
    node->right = buildBST(slow->next, tail);
    return node;
}
struct TreeNode* sortedListToBST(struct ListNode* head){
    if (!head)
        return NULL;
    else
        return buildBST(head, NULL);
}