1375-number-of-times-binary-string-is-prefix-aligned.js

/**
 * 1375. Number of Times Binary String Is Prefix-Aligned
 * https://leetcode.com/problems/number-of-times-binary-string-is-prefix-aligned/
 * Difficulty: Medium
 *
 * You have a 1-indexed binary string of length n where all the bits are 0 initially. We will
 * flip all the bits of this binary string (i.e., change them from 0 to 1) one by one. You are
 * given a 1-indexed integer array flips where flips[i] indicates that the bit at index i will
 * be flipped in the ith step.
 *
 * A binary string is prefix-aligned if, after the ith step, all the bits in the inclusive range
 * [1, i] are ones and all the other bits are zeros.
 *
 * Return the number of times the binary string is prefix-aligned during the flipping process.
 */

/**
 * @param {number[]} light
 * @return {number}
 */
var numTimesAllBlue = function(flips) {
  let maxFlipped = 0;
  let result = 0;

  flips.forEach((position, step) => {
    maxFlipped = Math.max(maxFlipped, position);
    if (maxFlipped === step + 1) result++;
  });

  return result;
};