Leetcode 374. Guess Number Higher or Lower (Easy) (cpp)

Leetcode 374. Guess Number Higher or Lower (Easy) (cpp)

Tag: Binary Search

Difficulty: Easy

/*374. Guess Number Higher or Lower (Easy)We are playing the Guess Game. The game is as follows:I pick a number from 1 to n. You have to guess which number I picked.Every time you guess wrong, I'll tell you whether the number is higher or lower.You call a pre-defined API guess(int num) which returns 3 possible results (-1, 1, or 0):-1 : My number is lower 1 : My number is higher 0 : Congrats! You got it!Example:n = 10, I pick 6.Return 6.*/// Forward declaration of guess API.// @param num, your guess// @return -1 if my number is lower, 1 if my number is higher, otherwise return 0int guess(int num);class Solution {public:int guessNumber(int n) {int left = 1, right = n;while (left != right) {int mid = left / 2 + right / 2;            switch (guess(mid)) {               case 1: left = mid + 1; break;               case -1: right = mid - 1; break;               case 0: return mid;            }}return left;}};