leetcode

0 class MyCircularDeque {

1 const int n;

2 vector<int> q;

3

4 int size = 0;

5 int head = 0, tail = 0;

6

7 public:

8 MyCircularDeque(int k) : n(k), q(k) {}

9

10 bool insertFront(int value) {

11 if (size == n) return false;

12 q[head] = value;

13 head = (head + 1) % n;

14 size++;

15 return true;

16 }

17

18 bool insertLast(int value) {

19 if (size == n) return false;

20 tail = (tail - 1 + n) % n;

21 q[tail] = value;

22 size++;

23 return true;

24 }

25

26 bool deleteFront() {

27 if (!size) return false;

28 head = (head - 1 + n) % n;

29 size--;

30 return true;

31 }

32

33 bool deleteLast() {

34 if (!size) return false;

35 tail = (tail + 1) % n;

36 size--;

37 return true;

38 }

39

40 int getFront() const { return size ? q[(head - 1 + n) % n] : -1; }

41 int getRear() const { return size ? q[tail] : -1; }

42 bool isEmpty() const { return size == 0; }

43 bool isFull() const { return size == n; }

44 };