Leet Code Solution JAVA - Guess Number Higher or Lower

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 will tell you whether the number I picked is higher or lower than your guess.

You call a pre-defined API int guess(int num), which returns 3 possible results:

• -1: The number I picked is lower than your guess (i.e. pick < num).
• 1: The number I picked is higher than your guess (i.e. pick > num).
• 0: The number I picked is equal to your guess (i.e. pick == num).

Return the number that I picked.

 

Example 1:

Input: n = 10, pick = 6
Output: 6

Example 2:

Input: n = 1, pick = 1
Output: 1

Example 3:

Input: n = 2, pick = 1
Output: 1

Example 4:

Input: n = 2, pick = 2
Output: 2

 

Constraints:

• 1 <= n <= 231 - 1
• 1 <= pick <= n

My Code:

/** 

 * Forward declaration of guess API.

 * @param  num   your guess

 * @return      -1 if num is lower than the guess number

 *       1 if num is higher than the guess number

 *               otherwise return 0

 * int guess(int num);

 */

public class Solution extends GuessGame {

    public int guessNumber(int num) {

        int i=1, j=num, mid=1;

        

        while(i<=j){

            mid = i + (j-i) / 2;

            int result = guess(mid);

            if(result==1) i = mid+1;

            else if (result==-1) j = mid-1;

            else return mid;

        }

        

   

        return mid;

    }

}

Copyright © saras ojha