# 每天一道LeetCode--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 (-11, 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.

public int guessNumber(int n) {
return guessNumber(1, n);
}
/*递归*/
private  int guessNumber(int start,int end){
int mid=start+(end-start)/2;
if(guess(mid)==-1){
return guessNumber(start,mid-1);
}else
if(guess(mid)==1){
return guessNumber(mid+1,end);
}else{
return mid;
}
}
}

public int guessNumber(int n) {

int low = 1;
int high = n;

while (low <= high) {
int mid = low+(high-low)/2;
int guessResult = guess(mid);
if (guessResult == 0)
return mid;

if (guessResult == 1)
low = mid+1;
else if (guessResult == -1)
high = mid-1;
}

return -1;
}

### 374. Guess Number Higher or Lower

posted @ 2016-11-27 10:33 破玉 阅读(...) 评论(...) 编辑 收藏