leetcode

Solution to some Leetcode problems written in C++
git clone git://git.dimitrijedobrota.com/leetcode.git
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2816.cpp (676B)

      1 class Solution {
      2     static ListNode *rev(ListNode *list) {
      3         ListNode *prev = nullptr, *next;
      4         while (list) {
      5             next = list->next;
      6             list->next = prev;
      7             prev = list;
      8             list = next;
      9         }
     10         return prev;
     11     }
     12 
     13   public:
     14     ListNode *doubleIt(ListNode *head) const {
     15         head = rev(head);
     16 
     17         ListNode *l = nullptr;
     18         int carry = 0;
     19         for (ListNode *p = head; p; l = p, p = p->next) {
     20             const int val = p->val * 2 + carry;
     21             p->val = val % 10;
     22             carry = val / 10;
     23         }
     24 
     25         if (carry) l->next = new ListNode(carry);
     26 
     27         return rev(head);
     28     }
     29 };