text: Undulating numbers | Python3 program to check whether a number is undulating or not ; Considering the definition with restriction that there should be at least 3 digits ; Check if all alternate digits are same or not . ; Driver Code
code: def isUndulating ( n ) : NEW_LINE INDENT if ( len ( n ) <= 2 ) : NEW_LINE INDENT return False NEW_LINE DEDENT for i in range ( 2 , len ( n ) ) : NEW_LINE INDENT if ( n [ i - 2 ] != n [ i ] ) : NEW_LINE INDENT return False NEW_LINE DEDENT DEDENT return True NEW_LINE DEDENT n = "1212121" NEW_LINE if ( isUndulating ( n ) ) : NEW_LINE INDENT print ( " Yes " ) NEW_LINE DEDENT else : NEW_LINE INDENT print ( " No " ) NEW_LINE DEDENT