MergeSortedArray.py

# Source : https://leetcode.com/problems/merge-sorted-array
# Author : Hamza Mogni
# Date   : 2022-01-20

#####################################################################################################
#
# 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.
#
# 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]
# Explanation: The arrays we are merging are [1,2,3] and [2,5,6].
# The result of the merge is [1,2,2,3,5,6] with the underlined elements coming from nums1.
#
# Example 2:
#
# Input: nums1 = [1], m = 1, nums2 = [], n = 0
# Output: [1]
# Explanation: The arrays we are merging are [1] and [].
# The result of the merge is [1].
#
# Example 3:
#
# Input: nums1 = [0], m = 0, nums2 = [1], n = 1
# Output: [1]
# Explanation: The arrays we are merging are [] and [1].
# The result of the merge is [1].
# Note that because m = 0, there are no elements in nums1. The 0 is only there to ensure the merge
# result can fit in nums1.
#
# 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?
#####################################################################################################

from typing import List


class Solution:
    def merge(self, nums1: List[int], m: int, nums2: List[int], n: int) -> None:
        """
        Do not return anything, modify nums1 in-place instead.
        """
        current = m + n - 1

        while m > 0 and n > 0:
            if nums1[m-1] > nums2[n-1]:
                nums1[current] = nums1[m-1]
                m -= 1
            else:
                nums1[current] = nums2[n-1]
                n -= 1

            current -= 1

        while n > 0:
            nums1[current] = nums2[current]
            current -= 1
            n -= 1
        print(nums1)


s = Solution()
s.merge([5, 5, 6, 0, 0, 0], 3, [1, 9, 11], 3)