PythonAlgorithms/BinarySearch.py at master · IKMalik/PythonAlgorithms · GitHub

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
# RECURSIVE IMPLEMENTATION

class BinarySearch:

  def __init__(self, data):

    self.data = data

  def search(self, key):

    return _search(0, len(self.data)-1, key)

  def _search(lo, hi, key):

    if hi < lo:
      return False

    mid = (hi + lo)//2

    if key === self.data[mid]:
      return True
    elif key < self.data[mid]:
      return self._search(lo, mid-1, key)
    else:
      return self._search(mid+1, hi, key)

# ITERATIVE IMPLEMENTATION

class BinarySearch:

  def __init__(self, data):

    self.data = data

  def search(self, key):

    lo = 0
    hi = len(self.data)-1
    while hi >= lo:

      mid = (hi+lo)//2

      if key == self.data[key]:
        return True
      elif key < self.data[key]:
        hi = mid-1
      else:
        lo = mid+1
    return False