Easy

Merge Sorted Array

Updated Jan 31, 2026

Problem

You are given two integer arrays nums1 and nums2, sorted in non-decreasing order, and two integers m and n, representing the number of elements in nums1 and nums2 respectively.

Merge nums1 and nums2 into a single array sorted in non-decreasing order.

The final sorted array should not be returned by the function, but instead be stored inside the array nums1. To accommodate this, nums1 has a length of m + n, where the first m elements denote the elements that should be merged, and the last n elements are set to 0 and should be ignored. nums2 has a length of n.

Constraints

nums1.length == m + n
nums2.length == n
0 <= m, n <= 200
1 <= m + n <= 200
-10^9 <= nums1[i], nums2[j] <= 10^9

Follow Up

Can you come up with an algorithm that runs in O(m + n) time?

Examples

Example 1

Input: nums1 = [1,2,3,0,0,0], m = 3, nums2 = [2,5,6], n = 3

Output: [1,2,2,3,5,6]

The arrays we are merging are [1,2,3] and [2,5,6].

Example 2

Input: nums1 = [1], m = 1, nums2 = [], n = 0

Output: [1]

Example 3

Input: nums1 = [0], m = 0, nums2 = [1], n = 1

Output: [1]

Function Signature

def merge(self, nums1: list[int], m: int, nums2: list[int], n: int) -> None

How to Submit

Implement a Solution class with a merge method.

Your method will be called with the input parameters and should return the answer.