Leetcode•Jul 21, 2025

Longest Continuous Increasing Subsequence

Hazrat Ali

Leetcode

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.


Solution
/**
 * @param {number[]} nums
 * @return {number}
 */
const findLengthOfLCIS = nums => {
  if (!nums || nums.length === 0) {
    return 0;
  }

  let max = 1;
  let current = 1;

  for (let i = 1; i < nums.length; i++) {
    if (nums[i] > nums[i - 1]) {
      current++;
      max = Math.max(max, current);
    } else {
      current = 1;
    }
  }

  return max;
};




Comments