153. Find Minimum in Rotated Sorted Array

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.

Solution 1 Binary Search

public static int findMin(int[] nums) {int start = 0;int end = nums.length - 1;while (start < end) {int mid = (start + end) / 2;if (nums[mid] <= nums[end]) {//can be <end = mid;} else {start = mid + 1;}}return nums[end];}

Solution 2 Recursion

public static int findMin2(int[] nums) {return search(nums, 0, nums.length - 1);}//Recursionpublic static int search(int[] nums, int start, int end) {if (start == end) {return nums[start];}int mid = (start + end) / 2;if (nums[mid] <= nums[end]) {return search(nums, start, mid);} else {return search(nums, mid + 1, end);}}