CA 16 - Guess the Number Higher or Lower

1.Problem Understanding

Need to guess a number from 1 to n.
You have an API:
guess(num)

It returns:

-1 → your guess is too high
1 → your guess is too low
0 → correct

2.Idea
Range is sorted (1 to n)
You get direction feedback (higher/lower)

3.Approach
Use:
low = 1
high = n
Each time:
Pick mid
Ask API
Narrow range

4.Example
n = 10, pick = 6
Steps:
mid = 5 → too low → go right
mid = 8 → too high → go left
mid = 6 → correct

5.Algorithm
Start with range [1, n]
While low ≤ high:
mid = (low + high) // 2
call guess(mid)
adjust range
Return mid when correct