3349. Adjacent Increasing Subarrays Detection I

Given an array nums of n integers and an integer k, determine whether there exist two adjacent subarrays of length k such that both subarrays are strictly increasing. Specifically, check if there are two subarrays starting at indices a and b (a < b), where:

• Both subarrays nums[a..a + k - 1] and nums[b..b + k - 1] are strictly increasing.
• The subarrays must be adjacent, meaning b = a + k.

Return true if it is possible to find two such subarrays, and false otherwise.

A subarray is a contiguous non-empty sequence of elements within an array.

class Solution {
public:
    bool hasIncreasingSubarrays(vector<int>& nums, int k) {
        deque<int> dq, dqq;
        for(int i = 0; i < nums.size(); i++) {
            while(dq.size() and nums[dq.back()] >= nums[i]) dq.pop_back();
            while(dq.size() and dq.front() <= i - k) dq.pop_front();
            while(dqq.size() and dqq.front() <= i - 2 * k) dqq.pop_front();
            dq.push_back(i);
            if(dq.size() == k) {
                dqq.push_back(i-k+1);
                if(dqq[0] == i - 2 * k + 1) return true;
            }
        }
        return false;
    }
};