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153. Find Minimum in Rotated Sorted Array

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Problem Statement

153. Find Minimum in Rotated Sorted Array

Medium


Suppose an array of length n sorted in ascending order is rotated between 1 and n times. For example, the array nums = [0,1,2,4,5,6,7] might become:

Notice that rotating an array [a[0], a[1], a[2], ..., a[n-1]] 1 time results in the array [a[n-1], a[0], a[1], a[2], ..., a[n-2]].

Given the sorted rotated array nums of unique elements, return the minimum element of this array.

You must write an algorithm that runs in O(log n) time.

 

Example 1:

Input: nums = [3,4,5,1,2]
Output: 1
Explanation: The original array was [1,2,3,4,5] rotated 3 times.

Example 2:

Input: nums = [4,5,6,7,0,1,2]
Output: 0
Explanation: The original array was [0,1,2,4,5,6,7] and it was rotated 4 times.

Example 3:

Input: nums = [11,13,15,17]
Output: 11
Explanation: The original array was [11,13,15,17] and it was rotated 4 times. 

 

Constraints:

Java

Source file
class Solution {
    public int findMin(int[] nums) {
        int n = nums.length, lt = 0, rt = n - 1;
        while(lt != rt){
            int mid = (lt + rt) / 2;
            if(nums[mid] < nums[rt])
                rt = mid;
            else lt = mid + 1;
        }
        return nums[lt];
    }
}