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Abhishek Chaudhary

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# Binary Prefix Divisible By 5

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]`, then `x0 = 1`, `x1 = 2`, and `x2 = 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 either `0` or `1`.

SOLUTION:

``````class Solution:
def prefixesDivBy5(self, nums: List[int]) -> List[bool]:
val = 0
op = []
for num in nums:
val = 2 * val + num
if val % 5 == 0:
op.append(True)
else:
op.append(False)
return op
``````