1018. Binary Prefix Divisible By 5-可被 5 整除的二进制前缀

Given an array A of 0s and 1s, consider N_i: the i-th subarray from A[0] to A[i] interpreted as a binary number (from most-significant-bit to least-significant-bit.)

Return a list of booleans answer, where answer[i] is true if and only if N_i is divisible by 5.

Example 1:
Input: [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: [1,1,1]
Output: [false,false,false]

Example 3:
Input: [0,1,1,1,1,1]
Output: [true,false,false,false,true,false]

Example 4:
Input: [1,1,1,0,1]
Output: [false,false,false,false,false]

Note:

• 1 <= A.length <= 30000
• A[i] is 0 or 1

Solution in python:

class Solution:
    def prefixesDivBy5(self, A: List[int]) -> List[bool]:
        result = []
        v = 0
        for i in A:
            v += i
            if v % 5 == 0:
                result.append(True)
            else:
                result.append(False)
            v *= 2
        return result