class Solution {
public:

    int count(ListNode* node){
        int len = 0;
        while (node)
            len++,  node = node->next;
        return len;
    }

    vector<ListNode*> splitListToParts(ListNode* root, int k) {
        vector<ListNode*> head(k, nullptr), tail(k, nullptr);
        if (!root)  return head;
        int len = count(root);

        auto p = root;
        for (int i = 0; i<k; i++)
            for (int j = 0; j < len / k + (i < len % k); j++){
                if (head[i] != nullptr)
                    tail[i]->next = p, tail[i] = p;
                else
                    head[i] = p, tail[i] = p;
                p = p->next;
            }

        for (int i = 0; i<k; i++)
            if (tail[i])    tail[i]->next = nullptr;

        return head;
    }
};