Number of ways to insert two pairs of parentheses into a string of N characters | Function to return the number of ways to insert the bracket pairs ; Driver code
def cntWays ( string , n ) : NEW_LINE INDENT x = n + 1 ; NEW_LINE ways = x * x * ( x * x - 1 ) // 12 ; NEW_LINE return ways ; NEW_LINE DEDENT if __name__ == " _ _ main _ _ " : NEW_LINE INDENT string = " ab " ; NEW_LINE n = len ( string ) ; NEW_LINE print ( cntWays ( string , n ) ) ; NEW_LINE DEDENT