human
Can you provide a code to count distinct sequences obtained by replacing all elements of subarrays having equal first and last elements with the first element any number of times and the other steps required given the following:
Count distinct sequences obtained by replacing all elements of subarrays having equal first and last elements with the first element any number of times | Function to count number of sequences satisfying the given criteria.
Stores the index of the last occurrence of the element.
Initialize an array to store the number of different sequences that are possible of length i.
Base Case.
If no operation is applied on ith element.
If operation is applied on ith element.
Update the last occurrence of curEle.
Finally , prthe answer.
Driver Code"
How can the above be solved in Python?
assistant
#Here is code to count distinct sequences obtained by replacing all elements of subarrays having equal first and last elements with the first element any number of times and the other steps required.
 def countPossiblities ( arr , n ) :
	lastOccur = [ - 1 ] * 100000
	dp = [ 0 ] * ( n + 1 )
	dp [ 0 ] = 1
	for i in range ( 1 , n + 1 ) :
		curEle = arr [ i - 1 ]
		dp [ i ] = dp [ i - 1 ]
		if ( lastOccur [ curEle ] != - 1 and lastOccur [ curEle ] < i - 1 ) :
			dp [ i ] += dp [ lastOccur [ curEle ] ]
		lastOccur [ curEle ] = i
	print ( dp [ n ] )
if __name__ == ' _ _ main _ _ ' :
	arr = [ 1 , 2 , 1 , 2 , 2 ]
	N = len ( arr )
	countPossiblities ( arr , N )