(This problem is an interactive problem.)
You may recall that an array
arr is a mountain array if and only if:
arr.length >= 3
0 < i < arr.length - 1such that:
arr < arr < ... < arr[i - 1] < arr[i]
arr[i] > arr[i + 1] > ... > arr[arr.length - 1]
Given a mountain array
mountainArr, return the minimum
index such that
mountainArr.get(index) == target. If such an
index does not exist, return
You cannot access the mountain array directly. You may only access the array using a
MountainArray.get(k)returns the element of the array at index
MountainArray.length()returns the length of the array.
Submissions making more than
100 calls to
MountainArray.get will be judged Wrong Answer. Also, any solutions that attempt to circumvent the judge will result in disqualification.
Input: array = [1,2,3,4,5,3,1], target = 3 Output: 2 Explanation: 3 exists in the array, at index=2 and index=5. Return the minimum index, which is 2.
Input: array = [0,1,2,4,2,1], target = 3 Output: -1 Explanation: 3 does not exist in
the array,so we return -1.
3 <= mountain_arr.length() <= 104
0 <= target <= 109
0 <= mountain_arr.get(index) <= 109