Syntax error Program to check whether we can split list into consecutive increasing sublists or not in Python

Program to check whether we can split list into consecutive increasing sublists or not in Python

Suppose we have a list of numbers called nums and that is sorted in non-decreasing order, we have to check whether it can be split into any number of subsequences such that each subsequence has at minimum length of 3 and that is consecutively increasing.

So, if the input is like nums = [2, 3, 4, 4, 5, 6, 7], then the output will be True, as we can split the list to [2, 3, 4] and [4, 5, 6, 7].

To solve this, we will follow these steps −

  • counts := A map that contains elements of nums and its counts
  • starts := a new list
  • ends := a new list
  • for each x in the items of the count in sorted order, do
    • if count[x] > count[x - 1], then
      • l := list of size (count[x] - count[x - 1]) and fill with x
      • insert l into starts
    • if count[x] > count[x + 1], then
      • l := list of size (count[x] - count[x + 1]) and fill with x
      • insert l into starts
  • return true when all (start, end) pair satisfies (start + 2 <= end), otherwise return false

Example (Python)

Let us see the following implementation to get better understanding −

 Live Demo

from collections import Counter
class Solution:
   def solve(self, nums):
      count = Counter(nums)
      starts = []
      ends = []
      for x in sorted(count):
         if count[x] > count[x - 1]:
            starts.extend([x] * (count[x] - count[x - 1]))
         if count[x] > count[x + 1]:
            ends.extend([x] * (count[x] - count[x + 1]))
      return all(s + 2 <= e for s, e in zip(starts, ends))
ob = Solution()
nums = [2, 3, 4, 4, 5, 6, 7]
print(ob.solve(nums))

Input

[6, 7, 5, 10, 13], 2

Output

True
Updated on: 2020-12-12T10:30:32+05:30

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