algos/py/week_1_merge_sort.py

38 lines
656 B
Python

def merge(a, b):
"""Merges two sorted lists"""
i, j = 0, 0
r = []
while i < len(a) and j < len(b):
if a[i] < b[j]:
r.append(a[i])
i += 1
else:
r.append(b[j])
j += 1
while i < len(a):
r.append(a[i])
i += 1
while j < len(b):
r.append(b[j])
j += 1
return r
def merge_sort(v):
length = len(v)
if length <= 1:
return v
half_length = length // 2
a = merge_sort(v[:half_length])
b = merge_sort(v[half_length:])
return merge(a, b)
if __name__ == "__main__":
print(merge_sort([42, 12, 3, 1, 5]))