human
Find lost element from a duplicated array | Function to find missing element based on binary search approach . arr1 [ ] is of larger size and N is size of it . arr1 [ ] and arr2 [ ] are assumed to be in same order ..
special case , for only element which is missing in second array.
special case , for first element missing.
Initialize current corner points.
loop until lo < hi.
If element at mid indices are equal then go to right subarray.
if lo , hi becomes contiguous , break.
missing element will be at hi index of bigger array.
This function mainly does basic error checking and calls findMissingUtil.
Driver Code"
Solution in Python:
 ... What is a code to find lost element from a duplicated array and the other steps required?
assistant
#Here is code to find lost element from a duplicated array and the other steps required.
 def findMissingUtil ( arr1 , arr2 , N ) :
	if N == 1 :
		return arr1 [ 0 ] ;
	if arr1 [ 0 ] != arr2 [ 0 ] :
		return arr1 [ 0 ]
	lo = 0
	hi = N - 1
	while ( lo < hi ) :
		mid = ( lo + hi ) / 2
		if arr1 [ mid ] == arr2 [ mid ] :
			lo = mid
		else :
			hi = mid
		if lo == hi - 1 :
			break
	return arr1 [ hi ]
def findMissing ( arr1 , arr2 , M , N ) :
	if N == M - 1 :
		print ( " Missing ▁ Element ▁ is " , findMissingUtil ( arr1 , arr2 , M ) )
	elif M == N - 1 :
		print ( " Missing ▁ Element ▁ is " , findMissingUtil ( arr2 , arr1 , N ) )
	else :
		print ( " Invalid ▁ Input " )
arr1 = [ 1 , 4 , 5 , 7 , 9 ]
arr2 = [ 4 , 5 , 7 , 9 ]
M = len ( arr1 )
N = len ( arr2 )
findMissing ( arr1 , arr2 , M , N )