LeetCode: Minimum Changes To Make Alternating Binary String Solution

Approach

Create 2 possible output

,

Calculate the number of steps from

to each of those

Find min between 2 of them

Implementation

1/**
2 * @param {string} s
3 * @return {number}
4 */
5var minOperations = function (s) {
6  const N = s.length
7  const chars = s.split("").map(Number)
8  const s1 = Array.from({ length: N }, (_, i) => (i % 2 === 0 ? 1 : 0))
9  const s2 = Array.from({ length: N }, (_, i) => (i % 2 === 0 ? 0 : 1))
10  return Math.min.apply(
11    null,
12    chars.reduce(
13      (acc, el, i) => [
14        acc[0] + (el !== s1[i] ? 1 : 0),
15        acc[1] + (el !== s2[i] ? 1 : 0),
16      ],
17      [0, 0]
18    )
19  )
20}