Suppose an array sorted in ascending order is rotated at some pivot unknown to you beforehand.
(i.e., 0 1 2 4 5 6 7 might become 4 5 6 7 0 1 2).
Find the minimum element.
You may assume no duplicate exists in the array.

思路：二分法，每次看中点是在rotate后的哪一段，然后移动left或right端点。

public int findMin(int[] nums) {
    if (nums == null || nums.length == 0) {
        return 0;
    }

    int left = 0, right = nums.length - 1;
    while (left + 1 < right) {
        int middile = left + (right - left) / 2;
        if (nums[middile] > nums[right]) {
            left = middile;
        } else {
            right = middile;
        }
    }

    return Math.min(nums[left], nums[right]);
}