Problem description:

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

Example 1:

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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:

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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:

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class Solution {
public:
    int findLengthOfLCIS(vector<int>& nums) {
        int count= 0, res= 0;
        for(int i= 0; i< nums.size(); i++){
            if(i == 0 || nums[i-1]< nums[i])
                res= max(res, ++count);
            else
                count= 1;
        }
        return res;
    }
};

time complexity: $O(n)$
space complexity: $O(1)$
reference: