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

Source: leetcode | Difficulty: EASY
Tags: Data structures

Sorting

Amortized analysis

Greedy algorithms

Starter code: class Solution:
    def findUnsortedSubarray(self, nums: List[int]) -> int:
        

Solutions:
class Solution:

	def findUnsortedSubarray(self, nums):
		left = 1
		size = len(nums)
		if size == 0:
			return 0
		while left < size and nums[left - 1] <= nums[left]:
			left += 1
		if left == size:
			return 0
		left -= 1
		right = size - 1
		while right > 0 and nums[right] >= nums[right - 1]:
			right -= 1
		sub = nums[left:right + 1]
		min_ = min(sub)
		max_ = max(sub)
		for i in range(left):
			if nums[i] > min_:
				left = i
				break
		for i in range(size - 1, right, -1):
			if nums[i] < max_:
				right = i
				break
		return right - left + 1


class Solution(object):

	def findUnsortedSubarray(self, nums):
		nums = [float('-inf')] + nums + [float('inf')]
		left = 0
		while left < len(nums) - 1 and nums[left] <= nums[left + 1]:
			left += 1
		if left == len(nums) - 1:
			return 0
		min_num = min(nums[left + 1:])
		while nums[left] > min_num:
			left -= 1
		right = len(nums) - 1
		while right > 0 and nums[right - 1] <= nums[right]:
			right -= 1
		if right == 0:
			return 0
		max_num = max(nums[:right])
		while nums[right] < max_num:
			right += 1
		return right - left - 1


class Solution:

	def findUnsortedSubarray(self, nums):
		if len(nums) == 1:
			return 0
		start = -1
		end = -1
		for i in range(len(nums) - 1):
			if nums[i] > nums[i + 1]:
				start = i
				break
		for i in reversed(list(range(1, len(nums)))):
			if nums[i] < nums[i - 1]:
				end = i
				break
		if start == -1:
			return 0
		minimum = 10000000000000
		maximum = -10000000000000
		for i in range(start, end + 1):
			if nums[i] > maximum:
				maximum = nums[i]
			if nums[i] < minimum:
				minimum = nums[i]
		for i in range(0, len(nums)):
			if nums[i] > minimum:
				start = i
				break
		for i in reversed(list(range(len(nums)))):
			if nums[i] < maximum:
				end = i
				break
		return end - start + 1


class Solution:

	def findUnsortedSubarray(self, nums):
		n = len(nums)
		if n < 2:
			return 0
		left = n - 1
		for i in range(n - 1):
			if nums[i] > nums[i + 1]:
				left = i + 1
				break
		min_i = left
		for i in range(left + 1, n):
			if nums[i] < nums[min_i]:
				min_i = i
		right = 0
		for i in range(n - 1, 0, -1):
			if nums[i] < nums[i - 1]:
				right = i - 1
				break
		max_i = right
		for i in range(max_i - 1, -1, -1):
			if nums[i] > nums[max_i]:
				max_i = i
		for i in range(min_i):
			if nums[i] > nums[min_i]:
				min_i = i
				break
		for i in range(n - 1, max_i, -1):
			if nums[i] < nums[max_i]:
				max_i = i
				break
		length = max_i - min_i + 1
		return length if length > 0 else 0


class Solution(object):

	def findUnsortedSubarray(self, nums):
		(n, lst) = (len(nums), sorted(nums))
		for i in range(n):
			if lst[i] != nums[i]:
				L = i
				break
		else:
			return 0
		for i in range(n - 1, -1, -1):
			if lst[i] != nums[i]:
				R = i
				break
		return R - L + 1


class Solution:

	def findUnsortedSubarray(self, nums):
		n = len(nums)
		nums_sorted = sorted(nums)
		is_same = [a == b for (a, b) in zip(nums, nums_sorted)]
		return 0 if all(is_same) else n - is_same.index(False) - is_same[::-1].index(False)


class Solution:

	def findUnsortedSubarray(self, nums):
		lens = len(nums)
		t = nums
		t = sorted(t)
		print(nums)
		t1 = lens
		t2 = 0
		for i in range(lens - 1):
			if nums[i] != t[i]:
				t1 = i
				break
		for i in range(lens - 1, 0, -1):
			if nums[i] != t[i]:
				t2 = i
				break
		print(t2)
		return max(t2 - t1 + 1, 0)


class Solution:

	def findUnsortedSubarray(self, nums):
		a = sorted(nums)
		start = -1
		end = -1
		for i in range(len(a)):
			if a[i] != nums[i] and start == -1:
				start = i
			elif a[i] != nums[i]:
				end = i
		if start == -1:
			return 0
		return end - start + 1


class Solution:

	def findUnsortedSubarray(self, nums):
		sort_nums = sorted(nums)
		diff = list(map(lambda x, y: x - y, sort_nums, nums))
		(start, end) = (0, len(nums) - 1)
		while start < end:
			if diff[start] == 0:
				start += 1
			if diff[end] == 0:
				end -= 1
			if diff[start] and diff[end]:
				break
		if end > start:
			return end - start + 1
		else:
			return 0