Question
Formatted question description: https://leetcode.ca/all/374.html
374 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'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 :
Input: n = 10, pick = 6
Output: 6
Algorithm
Binary search.
Code
Java
public class Guess_Number_Higher_or_Lower {
public class Solution extends GuessGame {
public int guessNumber(int n) {
int low = 1;
int high = n;
while (low <= high) {
int mid = low + (high - low) / 2;
int res = guess(mid);
if (res == 0)
return mid;
else if (res < 0)
high = mid - 1;
else
low = mid + 1;
}
return -1;
}
}
}
// stub
class GuessGame {
public int guess(int i) {
return 0;
}
}