human
Sub | Function that counts all the sub - strings of length ' k ' which have all identical characters.
count of sub - strings , length , initial position of sliding window.
dictionary to store the frequency of the characters of sub - string.
increase the frequency of the character and length of the sub - string.
if the length of the sub - string is greater than K.
remove the character from the beginning of sub - string.
if the length of the sub string is equal to k and frequency of one of its characters is equal to the length of the sub - string i . e . all the characters are same increase the count.
display the number of valid sub - strings.
Driver code"
Solution in Python:

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Give me a code to sub and the other steps required?
assistant
#Here is code to sub and the other steps required.
 def solve ( s , k ) :
	count , length , pos = 0 , 0 , 0
	m = dict . fromkeys ( s , 0 )
	for i in range ( len ( s ) ) :
		m [ s [ i ] ] += 1
		length += 1
		if length > k :
			m [ s [ pos ] ] -= 1
			pos += 1
			length -= 1
		if length == k and m [ s [ i ] ] == length :
			count += 1
	print ( count )
if __name__ == " _ _ main _ _ " :
	s = " aaaabbbccdddd "
	k = 4
	solve ( s , k )