LeetCode Entry

Guess Number Higher Or Lower

16.11.2022 easy 2022 kotlin

override fun guessNumber(n:Int):Int {

https://leetcode.com/problems/guess-number-higher-or-lower/ easy

    override fun guessNumber(n:Int):Int {
       var lo = 1
       var hi = n
       while(lo <= hi) {
           val pick = lo + (hi - lo)/2
           val answer = guess(pick)
           if (answer == 0) return pick
           if (answer == -1) hi = pick - 1
           else lo = pick + 1
       }
       return lo
    }

This is a classic binary search algorithm. The best way of writing it is:

• use safe mid calculation (lo + (hi - lo)/2)
• use lo <= hi instead of lo < hi and mid+1/mid-1 instead of mid

Complexity: O(log(N)) Memory: O(1)