iframe-proxy | Sunbelt Computer Software

18 lines (15 loc) · 571 Bytes

def find_missing_number(nums):

"""Returns the missing number from a sequence of unique integers

in range [0..n] in O(n) time and space. The difference between

consecutive integers cannot be more than 1. If the sequence is

already complete, the next integer in the sequence will be returned.

>>> find_missing_number(i for i in range(0, 10000) if i != 1234)

1234

>>> find_missing_number([4, 1, 3, 0, 6, 5, 2])

"""

missing = 0

for i, num in enumerate(nums):

missing ^= num

missing ^= i + 1

return missing

Sunbelt Computer Software