human
Count of substrings of length K with exactly K distinct characters | Function to return the required count of substrings.
Store the count.
Store the count of distinct characters in every window.
Store the frequency of the first K length substring.
Increase frequency of i - th character.
If K distinct characters exist.
Traverse the rest of the substring.
Increase the frequency of the last character of the current substring.
Decrease the frequency of the first character of the previous substring.
If the character is not present in the current substring.
If the count of distinct characters is 0.
Return the count.
Driver code.
string str.
Integer K.
Print the count of K length substrings with k distinct characters"
Solution in Python:
assistant
#Here is code to count of substrings of length K with exactly K distinct characters and the other steps required.
 def countSubstrings ( str , K ) :
	N = len ( str )
	answer = 0
	map = { }
	for i in range ( K ) :
		map [ str [ i ] ] = map . get ( str [ i ] , 0 ) + 1
	if ( len ( map ) == K ) :
		answer += 1
	for i in range ( K , N ) :
		map [ str [ i ] ] = map . get ( str [ i ] , 0 ) + 1
		map [ str [ i - K ] ] -= 1
		if ( map [ str [ i - K ] ] == 0 ) :
			del map [ str [ i - K ] ]
		if ( len ( map ) == K ) :
			answer += 1
	return answer
if __name__ == ' _ _ main _ _ ' :
	str = " aabcdabbcdc "
	K = 3
	print ( countSubstrings ( str , K ) )