Problem

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.

You may assume no duplicate exists in the array.

Example 1:

Input: [3,4,5,1,2] 
Output: 1

Example 2:

Input: [4,5,6,7,0,1,2]
Output: 0

Solution

/**
 * @param {number[]} nums
 * @return {number}
 */
var findMin = function(nums) {
  var left = 0;
  var right = nums.length - 1;
  var mid = 0;
  while (left < right) {
    mid = Math.floor((left + right) / 2);
    if (nums[mid - 1] > nums[mid]) return nums[mid];
    if (nums[mid] < nums[left] || nums[mid] < nums[right]) {
      right = mid - 1;
    } else {
      left = mid + 1;
    }
  }
  return nums[left];
};

Explain:

nope.

Complexity:

• Time complexity : O(log(n)).
• Space complexity : O(1).