How we can find number is even or add without using arithmetic operations?

Answer 1

Well, modulo is likely the best way,
but since you said no arithmetic operators:

(All code here is done with Java)

You could use bitwise & operator.
if num & 1 is 0, the number is even!

Example/
int input = 5;
boolean isEven = ((input & 1) == 0);

You can also use the shift operators.

For example,

int input = 5;
if((input >> 1) << 1 == input)
// Number is Even!
else
// Number is odd!

This works because if you shift back with an odd number you will lose some data! (The final binary digit will be cut off)

As for a very inefficient method (Time to get creatively not creative):

You could cast the number to a string and check if the last digit is an odd number.

Like:
int input = 501;
String num = String.valueOf(input);

char digit = num.charAt(num.length() - 1);
// last digit

if (digit == '1' || digit == '3' .... etc

As you can see, this is very impractical. But works!

Answer 2

Maybe convert the number to a string and check if the last character is a 0, 2, 4, 6 or 8 for even, otherwise odd.

JS (regex): https://code.sololearn.com/W4v7H8KBY2f4/#js ;)

Answer 3

@Rrestoring Maybe I'm wrong, but how could that even be possible for negatives? You're right about positives (num&1==1 or 0). But how could it be -1? Of course, I'm probably completely wrong...

Answer 4

@A_Hook that's an awesome idea..
here is code of your idea in python
https://code.sololearn.com/cq2ax7ijfFuD/?ref=app

Answer 5

it can be possible using bitwise operator. Check out this code in c++.
https://code.sololearn.com/cVKzKy66yBNk/?ref=app

Answer 6

modulo operator will do it.

if (something % 2 == 0) will get an even number... else odd

why would you even consider without operators? your code would be terrible to look at.

Answer 7

@ J.G
Nope, nvm I'm wrong about that.
Just tested it in AIDE, it didn't seem to make a difference. So I gues the & operator doesn't take sign into account. (I assumed it did, atleast for Java).

Answer 8

if (n&1==1) odd

Answer 9

@Muhammed, double "=" needed

Answer 10

hey gaurav !according to me to find whether the no. is even or odd the best way is by doing programs on java

Answer 11

Well I understood this question as 'I want a negative but it looks like I'm subtracting something' and that's actually exactly what I suggest u do. Try, if u want -1, to do 1-2 instead, and then u can have ur negative number

Answer 12

There's a horror way also by multi-threading:
https://www.facebook.com/plugins/post.php?href=https%3A%2F%2Fwww.facebook.com%2Filp2013%2Fposts%2F1669269146457663&width=500