Solution to LeetCode 2034 Stock Price Fluctuation
LeetCode 2034
Stock Price Fluctuation (Medium). [link]
Use a HashMap to store and update the time stamp. Use SortedList to store the price in ascending order.
from sortedcontainers import SortedList
class StockPrice(object):
def __init__(self):
self.price = SortedList()
self.Hash = {}
self.currentTime = 0
def update(self, timestamp, price):
"""
:type timestamp: int
:type price: int
:rtype: None
"""
if timestamp in self.Hash:
self.price.discard(self.Hash[timestamp])
self.price.add(price)
self.Hash[timestamp] = price
self.currentTime = max(self.currentTime, timestamp)
def current(self):
"""
:rtype: int
"""
return self.Hash[self.currentTime]
def maximum(self):
"""
:rtype: int
"""
return self.price[-1]
def minimum(self):
"""
:rtype: int
"""
return self.price[0]
We can also use Min Heap and Max Heap to keep track of the maximum and minimum of the price.
class StockPrice(object):
def __init__(self):
self.maxPrice = []
self.minPrice = []
self.Hash = {}
self.currentTime = 0
def update(self, timestamp, price):
"""
:type timestamp: int
:type price: int
:rtype: None
"""
heappush(self.maxPrice, (-price, timestamp))
heappush(self.minPrice, (price, timestamp))
self.Hash[timestamp] = price
self.currentTime = max(self.currentTime, timestamp)
def current(self):
"""
:rtype: int
"""
return self.Hash[self.currentTime]
def maximum(self):
"""
:rtype: int
"""
while True:
price, timestamp = self.maxPrice[0]
if -price == self.Hash[timestamp]:
return -price
heappop(self.maxPrice)
def minimum(self):
"""
:rtype: int
"""
while True:
price, timestamp = self.minPrice[0]
if price == self.Hash[timestamp]:
return price
heappop(self.minPrice)
