human
Make largest palindrome by changing at most K | Returns maximum possible palindrome using k changes.
Initialize l and r by leftmost and rightmost ends.
first try to make palindrome.
Replace left and right character by maximum of both.
If k is negative then we can 't make  palindrome.
At mid character , if K > 0 then change it to 9.
If character at lth ( same as rth ) is less than 9.
If none of them is changed in the previous loop then subtract 2 from K and convert both to 9.
If one of them is changed in the previous loop then subtract 1 from K ( 1 more is subtracted already ) and make them 9.
Driver code"
Solution in Python:

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Can you provide a code to make largest palindrome by changing at most K and the other steps required?
assistant
#Here is code to make largest palindrome by changing at most K and the other steps required.
 def maximumPalinUsingKChanges ( strr , k ) :
	palin = strr [ : : ]
	l = 0
	r = len ( strr ) - 1
	while ( l <= r ) :
		if ( strr [ l ] != strr [ r ] ) :
			palin [ l ] = palin [ r ] =
				max ( strr [ l ] , strr [ r ] )
			k -= 1
		l += 1
		r -= 1
	if ( k < 0 ) :
		return " Not ▁ possible "
	l = 0
	r = len ( strr ) - 1
	while ( l <= r ) :
		if ( l == r ) :
			if ( k > 0 ) :
				palin [ l ] = '9'
		if ( palin [ l ] < '9' ) :
			if ( k >= 2 and palin [ l ] == strr [ l ] and palin [ r ] == strr [ r ] ) :
				k -= 2
				palin [ l ] = palin [ r ] = '9'
			elif ( k >= 1 and ( palin [ l ] != strr [ l ] or palin [ r ] != strr [ r ] ) ) :
				k -= 1
				palin [ l ] = palin [ r ] = '9'
		l += 1
		r -= 1
	return palin
st = "43435"
strr = [ i for i in st ]
k = 3
a = maximumPalinUsingKChanges ( strr , k )
print ( " " . join ( a ) )