Leetcode

Grammar

Internal functions

  • max, sum, map
  • reversed, sorted

Libraries

  • heapq

    import heapq
heapq.heapify(heap)
heapq.heappush(heap, v) # Min heap
heapq.heappush(heap, -v) # Max heap
heapq.heappush(heap, (v1, v2, v3))
heapq.heappop(heap)

  • re

    import re
re.split("[!?',;. ]", paragraph.lower())
re.sub("[!?',;. ]+", " ", paragraph.lower())
re.replace(' ', '', paragraph)

  • random

    import random
random.randrange(a, b) # a <= N < b
random.randint(a, b) # a <= N <= b

  • string

    chr(65) # 'A'
ord('B') - ord('A') # 1
"Hello".split() # ["Hello"]
"Hello World".split() # ["Hello", "World"]
list("Hello") # ['H', 'e', 'l', 'l', 'o']
"Hello".replace("o", "a") # "Hella"

Collections

  • defaultdict

    from collections import defaultdict
shown = defaultdict(int)
shown = defaultdict(list)
shown = defaultdict(dict)

  • Counter

    from collections import Counter
counter = Counter(paragraph)
items = list(counter.items())
items.sort(key = lambda x: (x[1], x[1]))

  • deque

    from collections import deque
queue = deque("0")
queue.append("1")
queue.appendleft("2")
queue.popleft()
queue.pop()
len(queue)

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