Check for Multiple Digits

[techdude2007]

I am trying to write a program that the user enters 4465 and the program checks to make sure that the same digits is not used twice in the number.  So in this case, the program would reject the number because there is 2 fours.  Any idea how to do this?

[Ralph]

This program does not allow one to enter any previously entered digit:

Code:

REM  Program omision error detected by Moneo and corrected by Ralph on June 1, 2008, as remarked on below

CLS
PRINT
PRINT " This program allows entering a number with from 1 to 10 digits, but "
PRINT " it only accepts entry of digits that have not been used before"
PRINT
PRINT " Type in your number, digit by digit.  When done, press Enter ";
DIM n(20) AS INTEGER

DO
again:
  k$ = "": WHILE k$ = "": k$ = INKEY$: WEND
  IF k$ = CHR$(13) THEN EXIT DO 'new line, from Moneo's input
  IF k$ < "0" OR k$ > "9" THEN GOTO again
  i = i + 1
  n(i) = VAL(k$)
  FOR j = 1 TO i - 1
    IF n(j) = n(i) THEN
      i = i - 1
      GOTO again
    END IF
  NEXT j
  PRINT k$;
LOOP 'modified, due to Moneo's input

system

[LPG]

You could go like this:

Code:

CLS
PRINT "ENTER A NUMBER AND I WILL TELL YOU IF THERE ARE ANY REPEATS:";
LINE INPUT A$
DIM NUMBERS(9) AS INTEGER
FOR B = 1 TO LEN(A$)
IF NUMBERS(VAL(MID$(A$,B,1))) = 1 THEN REPEAT = 1
IF NUMBERS(VAL(MID$(A$,B,1))) = 0 THEN NUMBERS(VAL(MID$(A$,B,1))) = 1
NEXT B
IF REPEAT = 1 THEN PRINT "THE NUMBER HAS A REPEAT"
IF REPEAT = 0 THEN PRINT "THE NUMBER DOSN'T HAVE ANY REPEATS"

SYSTEM

[Moneo]

Here's a version with more error checking and complete reporting of duplicated digits.

Regards..... Moneo

''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
dim dup(0 to 9)
input "Enter series of numbers "; n$
if n$="" then print "Error: null entry."ystem

for x=1 to len(n$)
    d$=mid$(n$,x,1)
    if d$<"0" or d$>"9" then print "Invalid digit(s) found."ystem
    d=val(d$)
    dup(d)=dup(d)+1
next x

for x=0 to 9
    if dup(x)>1 then gotdups=1:print "digit";x;"repeated";dup(x);"times."
next x
if gotdups=0 then print "No duplicate digits found."
system

[Ralph]

LPG and Moneo:
Seems as though techdude2007 has either not received any notification on any of our three posts, or that he has his answer(s) and believes that's the end of the story.  Nothing new, as I see this happen, now and then.  But, sometimes there is a valid reason for a long delay in answering...we'll see. 

[Dav]

Well, here's another one ...

Entry:                             

  INPUT "Enter a number: ", num      ' Get a number entry only
  num$ = STR$(num)                      ' Convert it to a string

  FOR s = 1 TO LEN(num$) - 1          ' Step through string.
    h$ = MID$(num$, s, 1)                ' Get a nibble here...
    t$ = MID$(num$, s + 1, 1)          ' ...and a nibble there.
    IF h$ = t$ THEN                        ' If both are the same,
      PRINT "Duplicate! Re-enter!"    ' then say so ...
      GOTO Entry                            ' ...and go back.
    END IF
  NEXT

  PRINT "No duplicates found."        ' If you make it here, all OK.

[Moneo]

Dav,

I think your solution assumes that the duplicate numbers are adjacent, like 4465. But, what if they are not adjacent, like 4654?

Regards..... Moneo

[Dav]

Oops...I read the thread too quickly and failed to fully see what was asked for. My apologies to all. 

- Dav

[Ralph]

Hi, Moneo!  What's wrong with my proposed solution?

[Moneo]

Ralph,

The way you have it just goes into an endless loop. What happens is that the chr$(13) is caught by the test if less than "0" or greater than "9", and thus the chr$(13) is never seen later by the LOOP UNTIL.

If you put the test for chr$(13) right after the INKEY line, then it works.
You can relace the LOOP UNTIL with a plain LOOP.

Regards..... Moneo