What is the time complexity of LeetCode 2771. Longest Non-decreasing Subarray From Two Arrays?

The Python solution on this page runs in O(n), where n is the length of the array.

What is the space complexity of LeetCode 2771. Longest Non-decreasing Subarray From Two Arrays?

The Python solution on this page uses O(1) auxiliary space.

Longest Non-decreasing Subarray From Two Arrays — LeetCode 2771 Python Solution

MediumArrayDynamic Programming

Problem: #2771
Pattern: Dynamic Programming
Reading time: 3 min
Source: leetcode.com

The problem

You are given two 0-indexed integer arrays nums1 and nums2 of length n. Let's define another 0-indexed integer array, nums3, of length n.

Example

Input: nums1 = [2,3,1], nums2 = [1,2,1]
Output: 2
Explanation: One way to construct nums3 is:

Python solution

Python

class Solution:
    def maxNonDecreasingLength(self, nums1: List[int], nums2: List[int]) -> int:
        n = len(nums1)
        f = g = 1
        ans = 1
        for i in range(1, n):
            ff = gg = 1
            if nums1[i] >= nums1[i - 1]:
                ff = max(ff, f + 1)
            if nums1[i] >= nums2[i - 1]:
                ff = max(ff, g + 1)
            if nums2[i] >= nums1[i - 1]:
                gg = max(gg, f + 1)
            if nums2[i] >= nums2[i - 1]:
                gg = max(gg, g + 1)
            f, g = ff, gg
            ans = max(ans, f, g)
        return ans

Complexity

Measure	Complexity
Time	O(n), where n is the length of the array
Space	O(1) auxiliary

Pattern: Dynamic Programming

Define a state, write the transition, and stop recomputing the same subproblem. LeetCode 2771. Longest Non-decreasing Subarray From Two Arrays is filed here on both counts: the reference solution below belongs to the algorithm family this hub collects, and LeetCode tags it Dynamic Programming.

The dynamic programming guide has the Python template for the pattern and the 481 LeetCode problems that use it.

Frequently asked questions

How hard is LeetCode 2771. Longest Non-decreasing Subarray From Two Arrays?: LeetCode 2771. Longest Non-decreasing Subarray From Two Arrays is rated Medium on LeetCode.
What is the time complexity of LeetCode 2771. Longest Non-decreasing Subarray From Two Arrays?: The Python solution on this page runs in O(n), where n is the length of the array.
What is the space complexity of LeetCode 2771. Longest Non-decreasing Subarray From Two Arrays?: The Python solution on this page uses O(1) auxiliary space.
What topics does LeetCode 2771. Longest Non-decreasing Subarray From Two Arrays cover?: LeetCode 2771. Longest Non-decreasing Subarray From Two Arrays is tagged Array and Dynamic Programming on LeetCode.