Leetcode 4. Median of Two Sorted Arrays

https://leetcode.com/problems/median-of-two-sorted-arrays/

Hard

There are two sorted arrays nums1 and nums2 of size m and n respectively.

Find the median of the two sorted arrays. The overall run time complexity should be O(log (m+n)).

You may assume nums1 and nums2 cannot be both empty.

Example 1:

nums1 = [1, 3]
nums2 = [2]

The median is 2.0

Example 2:

nums1 = [1, 2]
nums2 = [3, 4]

The median is (2 + 3)/2 = 2.5

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• 题目要求O( log(m+n) )，先写了个O( (m+n)log(m+n) )凑数。
• Built-in Functions — Python 3.7.2 documentation
  • https://docs.python.org/3/library/functions.html#sorted
  • sorted(iterable, *, key=None, reverse=False)
• Sorting HOW TO — Python 3.7.2 documentation
  • https://docs.python.org/3/howto/sorting.html#sortinghowto
  • Python lists have a built-in list.sort() method that modifies the list in-place. There is also a sorted() built-in function that builds a new sorted list from an iterable.
  • In this document, we explore the various techniques for sorting data using Python.

class Solution:
    def findMedianSortedArrays(self, nums1: List[int], nums2: List[int]) -> float:
        merge_nums = sorted( nums1 + nums2 ) # pay attention to the parameter
        
        n_nums = len( merge_nums )
        index = int( n_nums / 2 )
        
        if n_nums % 2 == 0:    
            return ( merge_nums[ index ] + merge_nums[ index - 1 ] ) / 2
        else:
            return ( merge_nums[ index ] )