class DualArrayDeque(BaseList):
def __init__(self, iterable=[]):
self._initialize()
self.add_all(iterable)
def _initialize(self):
self.front = ArrayStack()
self.back = ArrayStack()
def get(self, i):
if i < self.front.size():
return self.front.get(self.front.size() - i - 1)
else:
return self.back.get(i - self.front.size())
def set(self, i, x):
if i < self.front.size():
return self.front.set(self.front.size() - i - 1, x)
else:
return self.back.set(i - self.front.size(), x)
def add(self, i, x):
if i < self.front.size():
self.front.add(self.front.size() - i, x)
else:
self.back.add(i - self.front.size(), x)
self._balance()
def remove(self, i):
if i < self.front.size():
x = self.front.remove(self.front.size() - i - 1)
else:
x = self.back.remove(i - self.front.size())
self._balance()
return x
def _balance(self):
n = self.size()
mid = n // 2
if 3 * self.front.size() < self.back.size(
) or 3 * self.back.size() < self.front.size():
f = ArrayStack()
for i in range(mid):
f.add(i, self.get(mid - i - 1))
b = ArrayStack()
for i in range(n - mid):
b.add(i, self.get(mid + i))
self.front = f
self.back = b
def clear(self):
self.front.clear()
self.back.clear()
def size(self):
return self.front.size() + self.back.size()
class DualArrayDeque(BaseList):
def __init__(self, iterable=[]):
self._initialize()
self.add_all(iterable)
def _initialize(self):
self.front = ArrayStack()
self.back = ArrayStack()
def get(self, i):
if i < self.front.size():
return self.front.get(self.front.size() - i - 1)
else:
return self.back.get(i - self.front.size())
def set(self, i, x):
if i < self.front.size():
return self.front.set(self.front.size() - i - 1, x)
else:
return self.back.set(i - self.front.size(), x)
def add(self, i, x):
if i < self.front.size():
self.front.add(self.front.size() - i, x)
else:
self.back.add(i - self.front.size(), x)
self._balance()
def remove(self, i):
if i < self.front.size():
x = self.front.remove(self.front.size() - i - 1)
else:
x = self.back.remove(i - self.front.size())
self._balance()
return x
def _balance(self):
n = self.size()
mid = n // 2
if 3 * self.front.size() < self.back.size() or 3 * self.back.size() < self.front.size():
f = ArrayStack()
for i in range(mid):
f.add(i, self.get(mid - i - 1))
b = ArrayStack()
for i in range(n - mid):
b.add(i, self.get(mid + i))
self.front = f
self.back = b
def clear(self):
self.front.clear()
self.back.clear()
def size(self):
return self.front.size() + self.back.size()
