Today I have done leetcode's November LeetCoding Challenge with cpp.

November LeetCoding Challenge 24

Description

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 {
public:
  vector<bool> prefixesDivBy5(vector<int>& nums) {
    int current = 0;
    vector<bool> answer;
    answer.reserve(nums.size());
    for(auto n : nums) {
      current *= 2;
      current += n;
      current %= 5;
      answer.push_back(!current);
    }
    return answer;
  }
};

// Accepted
// 24/24 cases passed (0 ms)
// Your runtime beats 100 % of cpp submissions
// Your memory usage beats 37.19 % of cpp submissions (18.5 MB)