05 August 2008
1到n之间的数字，给一个API猜大小，二分
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/**
* 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 n) {
int left = 0;
int right = n;
while (left + 1 < right) {
int mid = left + (right - left) / 2;
if (guess(mid) == 0) {
return mid;
} else if (guess(mid) == 1) {
left = mid;
} else {
right = mid;
}
}
if (guess(left) == 0) {
return left;
}
return right;
}
}