Given an integer array arr, remove a subarray (can be empty) from arr such that the remaining elements in arr are non-decreasing.
Return the length of the shortest subarray to remove.
A subarray is a contiguous subsequence of the array.
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.
Constraints:
1 <= arr.length <= 1050 <= arr[i] <= 109class Solution {
public int findLengthOfShortestSubarray(int[] arr) {
int n = arr.length, lt = 0, rt;
for (rt = n - 1; rt > 0 && arr[rt - 1] <= arr[rt]; rt--)
;
int minRmLen = rt;
while (lt < rt && (lt == 0 || arr[lt - 1] <= arr[lt])) {
while (rt < n && arr[lt] > arr[rt])
rt++;
minRmLen = Math.min(minRmLen, rt - lt - 1);
lt++;
}
return minRmLen;
}
}