leetcode Guess Number Higher or Lower

leetcode Guess Number Higher or Lower 题目：https://leetcode.com/problems/guess-number-higher-or-lower/

猜数字

解题思路：二分查找算法

/**
	 * return -1 if my number is lower, 1 if my number is higher, otherwise return 0
	 * @param n
	 * @return
	 */
	public int guessNumber(int n) {
		int left=1,right=n;
		while(left<=right){
			int mid=(right-left)/2+left;
			int guess = guess(mid);
			if(guess==0){
				return mid;
			}else if(guess==-1){
				right=mid-1;
			}else if (guess==1){
				left=mid+1;
			}
		}
		return -1;
	}