Description
You are given a binary array nums
(0-indexed).
We define xi
as the number whose binary representation is the subarray nums[0..i]
(from most-significant-bit to least-significant-bit).
- For example, if
nums = [1,0,1]
, thenx0 = 1
,x1 = 2
, andx2 = 5
.
Return an array of booleans answer
where answer[i]
is true
if xi
is divisible by 5
.
Example 1:
Input: nums = [0,1,1] Output: [true,false,false] Explanation: The input numbers in binary are 0, 01, 011; which are 0, 1, and 3 in base-10. Only the first number is divisible by 5, so answer[0] is true.
Example 2:
Input: nums = [1,1,1] Output: [false,false,false]
Constraints:
1 <= nums.length <= 105
nums[i]
is either0
or1
.
Solution
Python3
class Solution:
def prefixesDivBy5(self, nums: List[int]) -> List[bool]:
n = len(nums)
prev = 0
res = []
for x in nums:
prev = prev * 2 + x
res.append(prev % 5 == 0)
return res