Missing Element in Sorted Array

Description

null

Solution(javascript)

/** 1: Binary Search
 * 求最大的index, 使 missingCount < k
 * @param {number[]} nums
 * @param {number} k
 * @return {number}
 */
const missingElement = function (nums, k) {
  const missingCount = (left, right) => nums[right] - nums[left] - (right - left)
  let left = 0
  let right = nums.length - 1
  let result = -1
  while (left <= right) {
    const middle = Math.floor(left + (right - left) / 2)
    const count = missingCount(0, middle)

    if (count < k) {
      left = middle + 1
      result = middle
    } else {
      right = middle - 1
    }
  }

  return k - missingCount(0, result) + nums[result]
}