//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: 
//
// 
// [4,5,6,7,0,1,2] if it was rotated 4 times. 
// [0,1,2,4,5,6,7] if it was rotated 7 times. 
// 
//
// 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: 
//
// 
// n == nums.length 
// 1 <= n <= 5000 
// -5000 <= nums[i] <= 5000 
// All the integers of nums are unique. 
// nums is sorted and rotated between 1 and n times. 
// 
// Related Topics Array Binary Search 👍 5153 👎 351


package leetcodeProblem.leetcode.editor.en

class FindMinimumInRotatedSortedArray {
    fun solution() {
    }

    //below code will be used for submission to leetcode (using plugin of course)
    //leetcode submit region begin(Prohibit modification and deletion)
    class Solution {
        fun findMin(nums: IntArray): Int {
            // If the list has just one element then return that element.
            if (nums.size == 1) {
                return nums[0]
            }

            // initializing left and right pointers.
            var left = 0
            var right = nums.size - 1

            // if the last element is greater than the first element then there is no rotation.
            // e.g. 1 < 2 < 3 < 4 < 5 < 7. Already sorted array.
            // Hence the smallest element is first element. A[0]
            if (nums[right] > nums[0]) {
                return nums[0]
            }

            // Binary search way
            while (right >= left) {
                // Find the mid element
                val mid = left + (right - left) / 2

                // if the mid element is greater than its next element then mid+1 element is the smallest
                // This point would be the point of change. From higher to lower value.
                if (nums[mid] > nums[mid + 1]) {
                    return nums[mid + 1]
                }

                // if the mid element is lesser than its previous element then mid element is the smallest
                if (nums[mid - 1] > nums[mid]) {
                    return nums[mid]
                }

                // if the mid elements value is greater than the 0th element this means
                // the least value is still somewhere to the right as we are still dealing with elements
                // greater than nums[0]
                if (nums[mid] > nums[0]) {
                    left = mid + 1
                } else {
                    // if nums[0] is greater than the mid value then this means the smallest value is somewhere to
                    // the left
                    right = mid - 1
                }
            }
            return -1
        }
    }
//leetcode submit region end(Prohibit modification and deletion)

}

fun main() {
    val result = FindMinimumInRotatedSortedArray.Solution()
        .findMin(
            intArrayOf(
                25,
                1,
                2,
                3,
                4,
                5,
                6,
                7,
                8,
                9,
                10,
                11,
                12,
                13,
                14,
                15,
                16,
                17,
                18,
                19,
                20,
                21,
                22,
                23,
                24
            )
        )
    println(result)
}
  

