Program to find length of contiguous strictly increasing sublist in Python

Suppose we have a list of numbers called nums, we have to find the maximum length of a contiguous strictly increasing sublist when we can remove one or zero elements from the list.

So, if the input is like nums = [30, 11, 12, 13, 14, 15, 18, 17, 32], then the output will be 7, as when we remove 18 in the list we can get [11, 12, 13, 14, 15, 17, 32] which is the longest, contiguous, strictly increasing sublist, and its length is 7.

To solve this, we will follow these steps−

• n := size of nums

• pre := a list of size n and fill with 1s

• for i in range 1 to n - 1, do

  • if nums[i] > nums[i - 1], then

    • pre[i] := pre[i - 1] + 1

• suff := a list of size n and fill with 1s

• for i in range n - 2 to -1, decrease by 1, do

  • if nums[i] < nums[i + 1], then

    • suff[i] := suff[i + 1] + 1

• ans := maximum value of maximum of pre and maximum of suff

• for i in range 1 to n - 1, do

  • if nums[i - 1] < nums[i + 1], then

    • ans := maximum of ans and (pre[i - 1] + suff[i + 1])

• return ans

Let us see the following implementation to get better understanding −

Example

 Live Demo

class Solution:    def solve(self, nums):       n = len(nums)       pre = [1] * n       for i in range(1, n - 1):          if nums[i] > nums[i - 1]:             pre[i] = pre[i - 1] + 1       suff = [1] * n       for i in range(n - 2, -1, -1):          if nums[i] < nums[i + 1]:             suff[i] = suff[i + 1] + 1                ans = max(max(pre), max(suff))                for i in range(1, n - 1):                   if nums[i - 1] < nums[i + 1]:                      ans = max(ans, pre[i - 1] + suff[i + 1])                return ans ob = Solution() nums = [30, 11, 12, 13, 14, 15, 18, 17, 32] print(ob.solve(nums))

Input

[30, 11, 12, 13, 14, 15, 18, 17, 32]

Output

7