human
Give me a code to find the lexicographically smallest string which satisfies the given condition and the other steps required given the following:
Find the lexicographically smallest string which satisfies the given condition | Function to return the required string.
First character will always be 'a.
To store the resultant string.
Since length of the string should be greater than 0 and first element of array should be 1.
Check one by one all element of given prefix array.
If the difference between any two consecutive elements of the prefix array is greater than 1 then there will be no such string possible that satisfies the given array . Also , string cannot have more than 26 distinct characters.
If difference is 0 then the ( i + 1 ) th character will be same as the ith character.
If difference is 1 then the ( i + 1 ) th character will be different from the ith character.
Return the resultant string.
Driver code"
How can the above be solved in Python?
assistant
#Here is code to find the lexicographically smallest string which satisfies the given condition and the other steps required.
 def smallestString ( N , A ) :
'
	ch = ' a '
	S = " "
	if ( N < 1 or A [ 0 ] != 1 ) :
		S = " - 1"
		return S
	S += str ( ch )
	ch = chr ( ord ( ch ) + 1 )
	for i in range ( 1 , N ) :
		diff = A [ i ] - A [ i - 1 ]
		if ( diff > 1 or diff < 0 or A [ i ] > 26 ) :
			S = " - 1"
			return S
		elif ( diff == 0 ) :
			S += ' a '
		else :
			S += ch
			ch = chr ( ord ( ch ) + 1 )
	return S
arr = [ 1 , 1 , 2 , 3 , 3 ]
n = len ( arr )
print ( smallestString ( n , arr ) )