154. Find Minimum in Rotated Sorted Array II

Posted 2020-11-13 wentiliangkaihua

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.

The array may contain duplicates.

Example 1:

Input: [1,3,5]
Output: 1

Example 2:

Input: [2,2,2,0,1]
Output: 0

Note:

• This is a follow up problem to Find Minimum in Rotated Sorted Array.
• Would allow duplicates affect the run-time complexity? How and why?

  class Solution {
      public int findMin(int[] nums) {
          int left = 0;
          int right = nums.length - 1;
          while (left < right) {
              int mid = left + (right - left) / 2;
              if (nums[mid] < nums[right]) {
                  right = mid;
              } else if (nums[mid] > nums[right]) {
                  left = mid + 1;
              } else {
                  --right;
              }
          }
          return nums[left];
      }
  }

  和search一样，如果有重复元素，right=mid，就right--减少数组元素。