Given an integer array arr, remove a subarray (can be empty) from arr such that the remaining elements in arr are non-decreasing.
A subarray is a contiguous subsequence of the array.
Return the length of the shortest subarray to remove.
Example 1:
Input: arr = [1,2,3,10,4,2,3,5]
Output: 3
Explanation: The shortest subarray we can remove is [10,4,2] of length 3. The remaining elements after that will be [1,2,3,3,5] which are sorted.
Another correct solution is to remove the subarray [3,10,4].
Example 2:
Input: arr = [5,4,3,2,1]
Output: 4
Explanation: Since the array is strictly decreasing, we can only keep a single element. Therefore we need to remove a subarray of length 4, either [5,4,3,2] or [4,3,2,1].
Example 3:
Input: arr = [1,2,3]
Output: 0
Explanation: The array is already non-decreasing. We do not need to remove any elements.
Example 4:
Input: arr = [1]
Output: 0
Constraints:
1 <= arr.length <= 10^5
0 <= arr[i] <= 10^9
class Solution:
    def findLengthOfShortestSubarray(self, arr: List[int]) -> int:
        l = []
        for x in arr:
            if not l or x >= l[-1]:
                l.append(x)
            else:
                break
        r = []
        for i in range(len(arr)-1, -1, -1):
            if not r or arr[i] <= r[-1]:
                r.append(arr[i])
            else:
                break
        r.reverse()
        if len(l) == len(arr):
            return 0
        sol = max(len(l), len(r))
        i, j = 0, 0
        # print(l, r)
        while i < len(l) and j < len(r):
            if l[i] <= r[j]:
                i += 1
            else:
                while j < len(r) and l[i] > r[j]:
                    j += 1
            # print(i, j)
            sol = max(sol, i+len(r)-j)
        return len(arr) - sol
class Solution:
    def findLengthOfShortestSubarray(self, arr: List[int]) -> int:
        l = []
        for x in arr:
            if not l or x >= l[-1]:
                l.append(x)
            else:
                break
        r = []
        for i in range(len(arr)-1, -1, -1):
            if not r or arr[i] <= r[-1]:
                r.append(arr[i])
            else:
                break
        r.reverse()
        if len(l) == len(arr):
            return 0
        sol = max(len(l), len(r))
        i, j = 0, 0
        # print(l, r)
        while i < len(l) and j < len(r):
            if l[i] <= r[j]:
                i += 1
            else:
                while j < len(r) and l[i] > r[j]:
                    j += 1
            # print(i, j)
            sol = max(sol, i+len(r)-j)
        return len(arr) - sol