[Freezo Begin]

So when i was in my computer ...
I have compared
this

if(contain(x,x) != -1)

With this

if(~contain(x,x))

They give me the same result , my questions is :

1- Why it gives the same result
2- who is faster ?

[fysiks]

Only one is correct . . . why are you playing with random characters with random code?

[Freezo Begin]

its not a random character ...

[fysiks]

To understand why it works, you have to understand signed integers and how they are represented as two's complement as well as a bitwise NOT.

The difference in speed, if any, is negligible (that basically means you'll never notice a difference in your program). I.e. the time it takes to execute the comparison is probably many order of magnitudes smaller than the the time it takes to run contain[i]().

Because it gives you no benefit, all you are doing by using it that way is obfuscating your code.

Originally Posted by Freezo Begin you are just saying bullshit .

No different from your excuses in that other thread . . .

[claudiuhks]

Sometimes ~0 is used for Unsigned Int types, to assign -1 value to an Unsigned type of variable.

int i = -1; // correct
unsigned int i = -1; // incorrect
unsigned int i = ~0; // correct

Related http://stackoverflow.com/questions/1...n-winsock2-h-c

[fysiks]

Originally Posted by claudiuhks Sometimes ~0 is used for Unsigned Int types, to assign -1 value to an Unsigned type of variable. int i = -1; // correct unsigned int i = -1; // incorrect unsigned int i = ~0; // correct

~0 is just the largest possible number when it's an unsigned int so it's not assigning a value of -1 (just to be clear) since -1 is not a possible value for an unsigned integer. I'm sure you could cast it to a signed in at some point but that's just confusing for people who don't understand how numbers are represented in binary.

[claudiuhks]

Originally Posted by fysiks ~0 is just the largest possible number when it's an unsigned int so it's not assigning a value of -1 (just to be clear) since -1 is not a possible value for an unsigned integer. I'm sure you could cast it to a signed in at some point but that's just confusing for people who don't understand how numbers are represented in binary.

Well yes, I meant the printable value. ~0, 0xFFFFFFFF, ... prints and formats -1 and can be assigned to unsigned types.
We should consider your post.

Overall, it has nothing special so it can be used along contain/ containi.

[fysiks]

Originally Posted by claudiuhks Overall, it has nothing special so it can be used along contain/ containi.

Like I said before, I wouldn't recommend it here because it obfuscates the code making it unreadable.

[hornet]

Originally Posted by Freezo Begin This doesnt help me at all . its not a random character ... you are just saying bullshit .

He's trying to work out what you actually want to avoid an XY problem, so don't be so disrespectful.

[Freezo Begin]

So its bitwise NOT ( ~ ) . So it will flip all the other bits ( 0 -> 1 ) .

@fysiks
Why you dont recommend to use it ?

@claudiuhks
So how can i get the time of execute ?