LeetCode 033 Search in Rotated Sorted Array

題目描述

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).

You are given a target value to search. If found in the array return its index, otherwise return -1.

You may assume no duplicate exists in the array.

---

代碼

    public int search(int[] nums, int target) {

        int l = 0, r = nums.length - 1;

        while (l <= r) {

            int m = (l + r) / 2;

            if (nums[m] == target)
                return m;
            if (nums[l] < nums[m]) {
                if (target <= nums[m] && target >= nums[l])
                    r = m - 1;
                else
                    l = m + 1;
            } else if (nums[l] > nums[m]) {
                if (target >= nums[l] || target <= nums[m])
                    r = m - 1;
                else
                    l = m + 1;
            } else
                l++;
        }
        return -1;
    }