export function countOccurrences(nums: number[], target: number): number {
  
  function firstOccurrence(value: number): number {
    let left = 0
    let right = nums.length

    while (left < right) {
      const mid = Math.floor((left + right) / 2)

      if (nums[mid] < value) left = mid + 1
      else right = mid
    }

    return left
  }

  const first = firstOccurrence(target)
  const last = firstOccurrence(target + 1)

  return first < nums.length && nums[first] === target 
    ? last - first 
    : 0
}