leetcode

0 class PeekingIterator : public Iterator {

1 int l_next = -1;

2 bool has_next = false;

3

4 public:

5 PeekingIterator(const vector<int> &nums) : Iterator(nums) {

6 if (!Iterator::hasNext()) return;

7 l_next = Iterator::next();

8 has_next = true;

9 }

10

11 int peek() { return l_next; }

12

13 int next() {

14 const int crnt = l_next;

15 has_next = Iterator::hasNext();

16 if (has_next) l_next = Iterator::next();

17 return crnt;

18 }

19

20 bool hasNext() const { return has_next; }

21 };