[Codility] BinaryGap

문제 설명

A binary gap within a positive integer N is any maximal sequence of consecutive zeros that is surrounded by ones at both ends in the binary representation of N.

For example, number 9 has binary representation 1001 and contains a binary gap of length 2. The number 529 has binary representation 1000010001 and contains two binary gaps: one of length 4 and one of length 3.
The number 20 has binary representation 10100 and contains one binary gap of length 1.
The number 15 has binary representation 1111 and has no binary gaps.
The number 32 has binary representation 100000 and has no binary gaps.

Write a function:

function solution(N);

that, given a positive integer N, returns the length of its longest binary gap.
The function should return 0 if N doesn't contain a binary gap.

For example, given N = 1041 the function should return 5, because N has binary representation 10000010001 and so its longest binary gap is of length 5.
Given N = 32 the function should return 0, because N has binary representation '100000' and thus no binary gaps.

Write an efficient algorithm for the following assumptions:

N is an integer within the range [1..2,147,483,647].

풀이

function solution(N) {
  const binary = N.toString(2);
  let answer = 0;
  let count = 0;
  for (let i = 0; i < binary.length; i++) {
    if (binary[i] == 0) {
      count += 1;
    } else if (binary[i] == 1) {
      if (count > answer) {
        answer = count;
        count = 0;
      } else {
        count = 0;
      }
    }
  }
  return answer;
}

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문제를 제출하고 나면 % 형식으로 얼마나 맞췄는지 알려준다.
프로그래머스처럼 따로 다른 사람들의 풀이를 보여주는 것 같지는 않았다.

영어 공부도 하면서 프로그래밍 공부도 같이한다고 생각하고 긍정적으로 풀어보자. 🙆