Shortest Unsorted Continuous Subarray - Array - Easy - LeetCode

Given an integer array, you need to find one continuous subarray that if you only sort this subarray in ascending order, then the whole array will be sorted in ascending order, too.

You need to find the shortest such subarray and output its length.

Example 1: Input: [2, 6, 4, 8, 10, 9, 15] Output: 5 Explanation: You need to sort [6, 4, 8, 10, 9] in ascending order to make the whole array sorted in ascending order. Note: Then the length of the input array is in the range [1, 10,000]. The input array may contain duplicates, so ascending order here means <=.

public class Solution {
 public int FindUnsortedSubarray(int[] nums) {
 var l=new int[nums.Length];
 int max = int.MinValue;
 for(int i=0;i<nums.Length;i++){ 
 if(max<nums[i]){
 max = nums[i]; 
 }
 l[i]=max;
 }
 
 var r=new int[nums.Length];
 int min = int.MaxValue;
 for(int i=nums.Length-1;i>=0;i--){ 
 if(min>nums[i]){
 min = nums[i]; 
 }
 r[i]=min; 
 }
 
 int left =0;
 for(int i=0;i<nums.Length;i++){
 if(l[i]!=r[i]){
 left = i;
 break;
 }
 }
 
 int right = 0;
 for(int i=nums.Length-1;i>=0;i--){
 if(l[i]!=r[i]){
 right = i;
 break;
 }
 }
 
 if(left == right){
 return 0;
 }
 
 return right-left+1;
 }
}

Time Complexity: O(n)

Space Complexity: O(n)