20170606-leetcode-581-Shortest Unsorted Continuous Subarray

1.Description

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 <=.
   解讀
   確定序列中無序子序列的長度

2.Solution

思路：可以通過排序的方式，確定左右邊界，返回即可

#Method：通過排序確定左右邊界
class Solution(object):
    def findUnsortedSubarray(self, nums):
        n, sorts,left,right= len(nums), sorted(nums),0,0
        if nums == sorts: return 0
        #找到左側邊界
        for i in range(n):
            if nums[i] != sorts[i]:
                l = i
                break
        #找到右側邊界
        for i in range(n-1,-1,-1):
            #print(i)
            if nums[i] != sorts[i]:
                r = i
                break
        return r - l + 1