674. Longest Continuous Increasing Subsequence

• Difficulty: Easy

• Topics: Array

• Similar Questions:

  • Number of Longest Increasing Subsequence

  • Minimum Window Subsequence

Problem:

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

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.

Solutions:

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

        ret = max(ret, right - left);

        return ret;
    }
};