q4_merge_median.py

class Solution:
    def findMedianSortedArrays(self, nums1: List[int], nums2: List[int]) -> float:
        merged_array = self.mergeArrays(nums1,nums2)
        #case0 if n+1 % 2 = 1... median = index position n+1/2 - 1
        #case1 if n+1 % 2 = 0 median = n/2 average of index n/2 and n/2 -1
       
        length = len(merged_array)
        
        if length % 2 == 0:
            n = length//2
            m = n-1
            median = (merged_array[n] + merged_array[m]) /2
            
        if length % 2 == 1:
            n = ((length + 1) //2) -1
            median = merged_array[n]
        
        return median
            
    # Merge arr1[0..n1-1] and  
    # arr2[0..n2-1] into  
    # arr3[0..n1+n2-1] 
    def mergeArrays(self,arr1, arr2) -> List[int]: 
        n1 = len(arr1)
        n2 = len(arr2)
        arr3 = [None] * (n1 + n2) 
        i = 0
        j = 0
        k = 0

        # Traverse both array 
        while i < n1 and j < n2: 

            # Check if current element  
            # of first array is smaller  
            # than current element of  
            # second array. If yes,  
            # store first array element  
            # and increment first array 
            # index. Otherwise do same  
            # with second array 
            if arr1[i] < arr2[j]: 
                arr3[k] = arr1[i] 
                k = k + 1
                i = i + 1
            else: 
                arr3[k] = arr2[j] 
                k = k + 1
                j = j + 1


        # Store remaining elements 
        # of first array 
        while i < n1: 
            arr3[k] = arr1[i]
            k = k + 1
            i = i + 1

        # Store remaining elements  
        # of second array 
        while j < n2: 
            arr3[k] = arr2[j]
            k = k + 1
            j = j + 1
        print("Array after merging") 
        for i in range(n1 + n2): 
            print(str(arr3[i]), end = " ") 
        return(arr3)