human
Give me a code to klee 's Algorithm (Length Of Union Of Segments of a line) and the other steps required given the following:
Klee 's Algorithm (Length Of Union Of Segments of a line) | Returns sum of lengths covered by union of given segments.
Initialize empty points container.
Create a vector to store starting and ending points.
Sorting all points by point value.
Initialize result as 0.
To keep track of counts of current open segments ( Starting point is processed , but ending point is not ).
Traverse through all points.
If there are open points , then we add the difference between previous and current point ..
If this is an ending point , reduce , count of open points ..
Driver code"
How can the above be solved in Python?
assistant
#Here is code to klee 's Algorithm (Length Of Union Of Segments of a line) and the other steps required.
 def segmentUnionLength ( segments ) :
	n = len ( segments )
	points = [ None ] * ( n * 2 )
	for i in range ( n ) :
		points [ i * 2 ] = ( segments [ i ] [ 0 ] , False )
		points [ i * 2 + 1 ] = ( segments [ i ] [ 1 ] , True )
	points = sorted ( points , key = lambda x : x [ 0 ] )
	result = 0
	Counter = 0
	for i in range ( 0 , n * 2 ) :
		if ( i > 0 ) & ( points [ i ] [ 0 ] > points [ i - 1 ] [ 0 ] ) & ( Counter > 0 ) :
			result += ( points [ i ] [ 0 ] - points [ i - 1 ] [ 0 ] )
		if points [ i ] [ 1 ] :
			Counter -= 1
		else :
			Counter += 1
	return result
if __name__ == ' _ _ main _ _ ' :
	segments = [ ( 2 , 5 ) , ( 4 , 8 ) , ( 9 , 12 ) ]
	print ( segmentUnionLength ( segments ) )