Longest Continuous Increasing Subsequence

Problem

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.

Solution

O(n) time, O(1) space

public class Solution {
    public int findLengthOfLCIS(int[] nums) {
        if (nums == null || nums.length == 0) return 0;
        int res = 0, count = 1;
        for (int i = 1; i < nums.length; i++) {
            if (nums[i] > nums[i - 1]) count++;
            else {
                res = Math.max(res, count);
                count = 1;
            }
        }
        return Math.max(count, res); //We still need to check count and res before we return
    }
}

Analysis

An easy problem solved in single pass
Notice that we need to compare count and res in case the longest subsequence is at the end