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.
很简单的题目，关键是。。。0,1,-1，我认为题目写反了。。。
/* The guess API is defined in the parent class GuessGame.
@param num, your guess
@return -1 if my number is lower, 1 if my number is higher, otherwise return 0
int guess(int num); */
public class Solution extends GuessGame {
public int guessNumber(int n) {
int start=1;
int end=n;
while(start<end){
int mid = start + (end-start)/2;
if(guess(mid) ==0){
return mid;
}
else if(guess(mid) ==-1){
end =mid;
}
else{
start = mid+1;
}
}
return start;
}
}
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