## 1018. Binary Prefix Divisible By 5

Given an array `A` of `0`s and `1`s, 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. `1 <= A.length <= 30000`
2. `A[i]` is `0` or `1`

## Rust Solution

``````struct Solution;

impl Solution {
fn prefixes_div_by5(a: Vec<i32>) -> Vec<bool> {
let mut x = 0;
let n = a.len();
let mut res: Vec<bool> = vec![false; n];
for i in 0..n {
x = (x * 2 + a[i]) % 5;
res[i] = x == 0;
}
res
}
}

#[test]
fn test() {
let a = vec![0, 1, 1];
let res = vec![true, false, false];
assert_eq!(Solution::prefixes_div_by5(a), res);
let a = vec![1, 1, 1];
let res = vec![false, false, false];
assert_eq!(Solution::prefixes_div_by5(a), res);
let a = vec![0, 1, 1, 1, 1, 1];
let res = vec![true, false, false, false, true, false];
assert_eq!(Solution::prefixes_div_by5(a), res);
let a = vec![1, 1, 1, 0, 1];
let res = vec![false, false, false, false, false];
assert_eq!(Solution::prefixes_div_by5(a), res);
}
``````

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