# 1574. Shortest Subarray to be Removed to Make Array Sorted
###### tags: `Leetcode` `Medium`
Link: https://leetcode.com/problems/shortest-subarray-to-be-removed-to-make-array-sorted/
## 思路
分三种情况讨论
从左边开始删 从右边开始删 以及删中间的
先考虑前两种情况 要嘛留left和它左边的 要嘛留right和它右边的

考虑第三种情况的时候其实就是在这两个subarray里面找两个点使得```arr[i]<=arr[j]``` 删掉```arr[i+1:j-1]```就能保证剩下的array是non-decreasing
## Code

class Solution {
public int findLengthOfShortestSubarray(int[] arr) {
int n = arr.length;
int left = 0, right = n-1;
while(left+1<n && arr[left]<=arr[left+1]){
left++;
}
if(left==n-1) return 0;
while(right>left && arr[right-1]<=arr[right]){
right--;
}
int ans = Math.min(right, n-left-1);

int i = 0;
int j = right;
while(i<=left && j<n){
if(arr[i]<=arr[j]){
ans = Math.min(ans, j-i-1);
i++;
}
else{
j++;
}
}
return ans;
}
}