Shortest Unsorted Continuous Subarray

Question

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:

1. Then length of the input array is in range [1, 10,000].
2. The input array may contain duplicates, so ascending order here means <=.

Tags

• Array

Thought

1. Sort the array
2. Compare the item in the original array and the sorted array with the same index and save the corresponding indices if the item is different.

Code

class Solution(object):
    def findUnsortedSubarray(self, nums):
        """
        :type nums: List[int]
        :rtype: int
        """
        if len(nums) <= 1:
            return 0
        sortNums = sorted(nums)
        start, end = None, None
        for i in xrange(len(nums)):
            if nums[i] != sortNums[i]:
                if start is None:
                    start = i
                else:
                    end = i
        if start is None:
            return 0
        else:
            return end - start + 1