LeetCode #641: Design Circular Deque
β’ 303 words β’ 2 min
LeetCode #641: Design Circular Deque:
python
class MyCircularDeque:
def __init__(self, k: int):
self.q = [None] * k
self.k = k
self.start = 0
self.end = 0
self.count = 0
## . . . .
## se
## . 1 . .
## s e
## . 2 3 .
## s e
def insertFront(self, value: int) -> bool:
if self.isEmpty():
self.q[self.start] = value
self.start = (self.start - 1) % self.k
self.end = (self.end + 1) % self.k
self.count += 1
return True
if self.isFull():
return False
self.q[self.start] = value
self.start = (self.start - 1) % self.k
self.count += 1
return True
def insertLast(self, value: int) -> bool:
if self.isEmpty():
self.q[self.end] = value
self.start = (self.start - 1) % self.k
self.end = (self.end + 1) % self.k
self.count += 1
return True
if self.isFull():
return False
self.q[self.end] = value
self.end = (self.end + 1) % self.k
self.count += 1
return True
def deleteFront(self) -> bool:
if self.isEmpty():
return False
self.start = (self.start + 1) % self.k
self.count -= 1
## self.q[self.start] = None
if self.count == 0:
self.end = self.start
return True
def deleteLast(self) -> bool:
if self.isEmpty():
return False
self.end = (self.end - 1) % self.k
self.count -= 1
## self.q[self.end] = None
if self.count == 0:
self.start = self.end
return True
def getFront(self) -> int:
if self.isEmpty():
return -1
return self.q[(self.start + 1) % self.k]
def getRear(self) -> int:
if self.isEmpty():
return -1
return self.q[self.end - 1 % self.k]
def isEmpty(self) -> bool:
return self.count == 0
def isFull(self) -> bool:
return self.count == self.k
# Your MyCircularDeque object will be instantiated and called as such:
# obj = MyCircularDeque(k)
# param_1 = obj.insertFront(value)
# param_2 = obj.insertLast(value)
# param_3 = obj.deleteFront()
# param_4 = obj.deleteLast()
# param_5 = obj.getFront()
# param_6 = obj.getRear()
# param_7 = obj.isEmpty()
# param_8 = obj.isFull()