[LeetCode] 674. Longest Continuous Increasing Subsequence

Given an unsorted array of integers, find the length of longest continuous increasing subsequence.

Example 1:

Input: [1,3,5,4,7]
Output: 3
Explanation: The longest continuous increasing subsequence is [1,3,5], its length is 3. 
Even though [1,3,5,7] is also an increasing subsequence, it's not a continuous one where 5 and 7 are separated by 4. 

Example 2:

Input: [2,2,2,2,2]
Output: 1
Explanation: The longest continuous increasing subsequence is [2], its length is 1. 

Note: Length of the array will not exceed 10,000.

Thought process:

Iterate through the array. Count the lengths of all increasing subsequences and keep track of the longest.

Solution:

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19

class Solution { public int findLengthOfLCIS(int[] nums) { if (nums.length == 0) { return 0; } int longest = 1; int count = 1; for (int i = 0; i < nums.length - 1; i++) { if (nums[i] < nums[i + 1]) { count++; longest = Math.max(longest, count); } else { count = 1; } } return longest; } }

Time complexity: O(n).