human
Can you provide a code to queries to find the Lower Bound of K from Prefix Sum Array with updates using Fenwick Tree and the other steps required given the following:
Queries to find the Lower Bound of K from Prefix Sum Array with updates using Fenwick Tree | Function to calculate and return the sum of arr [ 0. . index ].
Traverse ancestors of BITree [ index ].
Update the sum of current element of BIT to ans.
Update index to that of the parent node in getSum ( ) view by subtracting LSB ( Least Significant Bit ).
Function to update the Binary Index Tree by replacing all ancestors of index by their respective sum with val.
Traverse all ancestors and sum with ' val ' ..
Add ' val ' to current node of BIT.
Update index to that of the parent node in updateBit ( ) view by adding LSB ( Least Significant Bit ).
Function to construct the Binary Indexed Tree for the given array.
Initialize the Binary Indexed Tree.
Store the actual values in BITree [ ] using update ( ).
Function to obtain and return the index of lower_bound of k.
Store the Binary Indexed Tree.
Solve each query in Q.
Update the values of all ancestors of idx.
Driver Code"
How can the above be solved in Python?
assistant
#Here is code to queries to find the Lower Bound of K from Prefix Sum Array with updates using Fenwick Tree and the other steps required.
 def getSum ( BITree , index ) :
	ans = 0
	index += 1
	while ( index > 0 ) :
		ans += BITree [ index ]
		index -= index & ( - index )
	return ans
def updateBIT ( BITree , n , index , val ) :
	index = index + 1
	while ( index <= n ) :
		BITree [ index ] += val
		index += index & ( - index )
def constructBITree ( arr , n ) :
	BITree = [ 0 ] * ( n + 1 )
	for i in range ( n + 1 ) :
		BITree [ i ] = 0
	for i in range ( n ) :
		updateBIT ( BITree , n , i , arr [ i ] )
	return BITree
def getLowerBound ( BITree , arr , n , k ) :
	lb = - 1
	l = 0
	r = n - 1
	while ( l <= r ) :
		mid = l + ( r - l ) // 2
		if ( getSum ( BITree , mid ) >= k ) :
			r = mid - 1
			lb = mid
		else :
			l = mid + 1
	return lb
def performQueries ( A , n , q ) :
	BITree = constructBITree ( A , n )
	for i in range ( len ( q ) ) :
		id = q [ i ] [ 0 ]
		if ( id == 1 ) :
			idx = q [ i ] [ 1 ]
			val = q [ i ] [ 2 ]
			A [ idx ] += val
			updateBIT ( BITree , n , idx , val )
		else :
			k = q [ i ] [ 1 ]
			lb = getLowerBound ( BITree , A , n , k )
			print ( lb )
if __name__ == " _ _ main _ _ " :
	A = [ 1 , 2 , 3 , 5 , 8 ]
	n = len ( A )
	q = [ [ 1 , 0 , 2 ] , [ 2 , 5 , 0 ] , [ 1 , 3 , 5 ] ]
	performQueries ( A , n , q )