# 2393. Count Strictly Increasing Subarrays ###### tags: `Leetcode` `Medium` `Dynamic Programming` Link: https://leetcode.com/problems/count-strictly-increasing-subarrays/description/ ## 思路 $O(N)$ $O(N)$ ```dp[i]```表示以```i```结尾的最长strictly increasing subarray的长度 所有的```dp[i]```加在一起就是答案 空间复杂度可以简化为$O(1)$ ## Code ```java= class Solution { public long countSubarrays(int[] nums) { long[] dp = new long[nums.length]; Arrays.fill(dp, 1); long ans = dp[0]; for(int i=1; i<nums.length; i++){ if(nums[i]>nums[i-1]) dp[i] = dp[i-1]+1; ans += dp[i]; } return ans; } } ```