Returns count of ways to reach n - th stair using 1 or 2 or 3 steps .
def findStep ( n ) : NEW_LINE INDENT if ( n == 1 or n == 0 ) : NEW_LINE INDENT return 1 NEW_LINE DEDENT elif ( n == 2 ) : NEW_LINE INDENT return 2 NEW_LINE DEDENT else : NEW_LINE INDENT return findStep ( n - 3 ) + findStep ( n - 2 ) + findStep ( n - 1 ) NEW_LINE DEDENT DEDENT