im kinda confused on what exactly this means/does.
n is a parameter to a recursive function and the function works, but what does the & (bitwise operator) does. From what i can understand is that when n is eventually 1 then the recursive function is called for the last time and then it returns the result. Am i right?Code:if (n & 1) //action
When no one helps you out. Call google();
Lets say that (in binary) the variable n has the following contents:
01010101010101010101010101010101
When we perform the bitwise AND of that value with 1 which is:
00000000000000000000000000000001
... we get the resulting value:
00000000000000000000000000000001
...which will evaluate to 'true' for the purposes of the if test. Basically the test is determining if the low order bit is set.
"Owners of dogs will have noticed that, if you provide them with food and water and shelter and affection, they will think you are god. Whereas owners of cats are compelled to realize that, if you provide them with food and water and shelter and affection, they draw the conclusion that they are gods."
-Christopher Hitchens
Yes, but it really only means that when n = 0 it will endn is a parameter to a recursive function and the function works, but what does the & (bitwise operator) does. From what i can understand is that when n is eventually 1 then the recursive function is called for the last time and then it returns the result. Am i right?
n & 1 evaluates to 1 if the last bit in the number is set, and it evaluates to 0 if it is not. Since 1 means true and 0 means false, the action is performed if the last bit is set in the number. If n is unsigned, then (n & 1) will be true whenever n is odd, so whether n is eventually 1 or 3 or some other odd number doesn't matter. It will end when n is even.
so that means that 0 is considered an even number?
When no one helps you out. Call google();
n&1 is also the same as n%2
What is:Originally Posted by InvariantLoop
0000 0000
0000 0001 &
------------
?
What will happen to the loop when n=0?
Last edited by 7stud; 03-09-2006 at 06:07 PM.
>> so that means that 0 is considered an even number?
Yes, 0 is even because of the definitions of even and odd. http://en.wikipedia.org/wiki/Even_and_odd_numbers
So, if wikipedia had defined 0 as an odd number, would that affect what the loop does when n=0?
Last edited by 7stud; 03-09-2006 at 06:48 PM.
No. Your question doesn't really make sense given the context of my statement. I think you may have misunderstood my point.
0 is defined mathematically as an even number. A formal mathematical definition is that an integer i is even if it is exactly equal to 2*j where j is also an integer. All integers that are not even are odd. This definition can be expressed in a number of equivalent forms (eg a number i is even if the remainder one dividing it by 2 is zero).
Daved's link to wikipedia was for information, not a claim that life is defined by wikipedia.
An even number is a number that can be divided by 2 e.g. it doesn't leave any decimals/no remainder. Simple as that.
0/2 = 0
1/2 = 0.5
2/2 = 1
3/2 = 1.5
4/2 = 2
