console.clear()

const bigOlogn = (target, searchArray) => {
  let start = 0
  let end = searchArray.length - 1
  let middle = undefined
  let middleTempValue = undefined
  
  while (start <= end) {
    middle = Math.floor((start + end) / 2)
    middleTempValue = searchArray[middle]
    if (middleTempValue === target) {
      return middle // index
      // return middleTempValue // value
    }
    
    if (target > middleTempValue) {
      start = middle + 1
    }
    
    if (target < middleTempValue) {
      end = middle - 1
    }
  }
  
  return -1
}

const ary = [1, 2, 3, 5, 5, 5, 8, 9]
console.log(bigOlogn(9, ary))