Find Minimum in Rotated Sorted Array——LeetCode

Suppose a sorted array 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.

题目大意：给定一个有序数组，是经过旋转过的，不知道在哪儿旋转的，求数组最小元素。

解题思路：直接遍历可以，太low。二分搜索吧，有序数组旋转有个特征，旋转后面的元素比旋转点前面的所有元素都小。

Talk is cheap>>

    public int findMin(int[] nums) {

        if (nums == null || nums.length == 0) {

            return 0;

        }

        int low = 0;

        int high = nums.length - 1;

        int mid = 0;

        while (low <= high) {

            mid = (low + high) >> 1;

            int left = mid > 0 ? mid - 1 : 0;

            int right = mid < nums.length - 1 ? mid + 1 : nums.length - 1;

            if (nums[mid] <= nums[left] && nums[mid] <= nums[right]) {

                break;

            }

            if (nums[mid] >= nums[high]) {

                low = mid + 1;

            } else {

                high = mid - 1;

            }

        }

        return nums[mid];

    }