Odd or Even Integer?

[kaotickid]

I'm wondering if there's a code out there to distinguish between an odd and even integer. This is a problem from the Turing .PDF (Chapter 14, Question 17), it's pretty much done but I just need to put the code that distinguishes whether an integer is even or odd. Thanks

code:

var numbers : array 1 .. 10 of int for i : 1 .. 10     get numbers (i) end for for i : 1 .. 10     %How to distinguish between odd or even.     put numbers (i), "is an odd number."     %How to distinguish between odd or even.     put numbers (i), "is an even number." end for

[CodeMonkey2000]

Use the modulus operation( the % sign). It gives the remainder of two integer. (eg 3%2 =1 since 2*2=2 and we have a remainder of 1).

[A.J]

there's a function in math called 'mod' thats also recognized in turing.
x mod y gives the remainder when x is divided by y.
so 17 mod 5 will give 2, since 17/5= 3 remainder 2.

so for distinguishing between odd and even, just take the number mod 2.
if it is 0 (anything divisible by 2 always gives 0, since there isn't any remainder), its even.
Otherwise if it is 1 (if it is not divisible by 2 then it has a remainder of 1), its odd!
so:

Turing:

var x:int put "Enter a number:".. get x if x mod 2=0 then    put x," is a even number" else    put x," is an odd number" end if

Hope this helped

A.J

EDIT: CodeMonkey2000 beat me to it. Oh darn

[kaotickid]

Haha A.J, but thanks to both of you, A.J and CodeMonkey
Well my questions is answered

[Nyrd]

code:

var number : int := 5 if number mod 2 = 0 then  put "Even" else  put "odd" end if % This will display "odd"

That should do it
In case you're wondering, "mod" is the modulo function. It essentially finds the remainder when you divide the number by 2 (in this case).
--Remember, if you divide a number by 2 and there is no remainder it must be even!--

[Nyrd]

Wow, I was beat to it by two people . . .
For shame . . .

[agnivohneb]

A.J @ Tue Mar 18, 2008 8:48 pm wrote:

Turing:

var x:int put "Enter a number:".. get x if x mod 2=0 then    put x," is a even number" else    put x," is an odd number" end if

You could also use the div function and instead of equaling 0 it equals 1.

Turing:

var x:int put "Enter a number:".. get x if x div 2=1 then % Note the div and the 1    put x," is a even number" else    put x," is an odd number" end if

[HeavenAgain]

CodeMonkey2000 @ Tue Mar 18, 2008 9:47 pm wrote:

(eg 3%2 =1 since 2*2=2 and we have a remainder of 1).

2*2 = 2?

agnivohneb @ Tue Mar 18, 2008 10:07 pm wrote:

You could also use the div function and instead of equaling 0 it equals 1.

yes you could use div to check if its odd or even, but in your example .... well, you should take another look at it

code:

if x div 2 = 1 then  put "even" else  put "odd"

something is odd here

[agnivohneb]

ummmmm ... think ... think ... I give up!

[richcash]

Bitwise 'and' is a bit faster than modulus I think.

code:

if x & 1 then    put "even" else    put "odd" end if

agnivohneb, try putting in any even number other than 2 in your code. See the problem?

[Saad]

If you want to be crazy and go with some mutual recursion

Turing:

forward fcn isEven (n : int) : boolean forward fcn isOdd (n : int) : boolean body fcn isEven     if (n = 0) then         result true     else         result isOdd (n - 1)     end if end isEven body fcn isOdd     if (n = 0) then         result false     else         result isEven (n - 1)     end if end isOdd put isOdd (1) put isEven (1)

[agnivohneb]

Wait! ... Ha! I got it. I reject my last comment. I know what the problem is now. It is not accurate.

[A.J]

nice richcash
bits are the way to go.

as for you saad.......lets just say forget about mutual recursion for now, shall we

[CodeMonkey2000]

Wow talk about overkill.......