LeetCode 674. Longest Continuous Increasing Subsequence

Description

https://leetcode.com/problems/longest-continuous-increasing-subsequence/

Given an unsorted array of integers nums, return the length of the longest continuous increasing subsequence (i.e. subarray). The subsequence must be strictly increasing.

A continuous increasing subsequence is defined by two indices l and r (l < r) such that it is [nums[l], nums[l + 1], ..., nums[r - 1], nums[r]] and for each l <= i < r, nums[i] < nums[i + 1].

Example 1:

Input: nums = [1,3,5,4,7]
Output: 3
Explanation: The longest continuous increasing subsequence is [1,3,5] with length 3.
Even though [1,3,5,7] is an increasing subsequence, it is not continuous as elements 5 and 7 are separated by element
4.

Example 2:

Input: nums = [2,2,2,2,2]
Output: 1
Explanation: The longest continuous increasing subsequence is [2] with length 1. Note that it must be strictly
increasing.

Constraints:

• 1 <= nums.length <= 104
• -109 <= nums[i] <= 109

Explanation

Iterate the list and compare it with the previous number and reach a conclusion what is the longest continuous sequence.

Python Solution

class Solution:
    def findLengthOfLCIS(self, nums: List[int]) -> int:
        max_count = 0
        
        if not nums:
            return max_count
        
        prev = nums[0]
        count = 1
        
        for num in nums[1:]:
            if num > prev:
                count += 1
            else:
                max_count = max(max_count, count)
                count = 1
                        
            prev = num
            
        return max(max_count, count)