Cool

why do we need so many probing technique in hash table does a one probing technique us faster then another technique? why cant we just use linear probing and that's it what is differentiate between one probing technique to other probing technique

[OT] Has anyone taken Coursera courses?

Yes

[OT] Has anyone taken Coursera courses?

#ot

/get noendl

🤔

I personally use a mix of both that I label in my code as skipstone probing where I do linear probing by groups of 1 cache line and skip a defined amount of steps before redoing the same. It tries to consile both the cache friendliness of linear probing and its terrible tendency to make clusters

It means that the best case is linear probing and the worst case is not going round for 12 milliseconds because the hashmap is 94% full

https://h313.info/blog/cpp/2020/05/17/this-is-what-peak-hello-world-looks-like.html

Guys does anybody know how to declare a 64-bit integer in ANSI C? The long long int (which is 64-bits on most systems) is only available since C99 and long in ANSI C seems to be 32 bit. Is there any 64-bit integer in ANSI C?

Guys does anybody know how to declare a 64-bit integer in ANSI C? The long long int (which is 64-bits on most systems) is only available since C99 and long in ANSI C seems to be 32 bit. Is there any 64-bit integer in ANSI C?

Either #include <stdint.h> or pass -mabi=ilp64

stdint.h is not available in ANSI C AFAIK :/

C89/C90 assert.h Assertions ctype.h Tests auf bestimmte Zeichentypen errno.h Codes von Systemfehlern float.h Angaben zu den Wertbereichen von Gleitkommazahlen limits.h Angaben zu Beschränkungen des verwendeten Systems locale.h Einstellungen des Gebietsschemas math.h mathematische Funktionen setjmp.h erweiterte Sprungfunktionen signal.h Signalbehandlung stdarg.h Argumentbehandlung für variadische Funktionen stddef.h zusätzliche Typdefinitionen stdio.h Ein- und Ausgabe stdlib.h vermischte Standardfunktionen, u. a. Speicherverwaltung string.h Zeichenkettenoperationen time.h Datum und Uhrzeit Neu in C95 (auch: „NA1“) iso646.h alternative Schreibweisen für logische und bitweise Operatoren wchar.h Unterstützung für Unicode-Zeichen wctype.h wie ctype.h, für Unicode-Zeichen Neu in C99[1] complex.h Komplexe Zahlen fenv.h Einstellungen für das Rechnen mit Gleitkommazahlen inttypes.h Konvertierungs- und Formatierungsfunktionen für erweiterte Ganzzahltypen stdbool.h Unterstützung für Boolesche Variablen stdint.h plattformunabhängige Definition von Ganzzahltypen tgmath.h typgenerische Makros für mathematische Funktionen Neu in C11 stdalign.h Makros für die Speicherausrichtung von Objekten stdatomic.h Typen und Makros für atomare Operationen zwischen Threads stdnoreturn.h Definition des No-Return-Makros threads.h Unterstützung für Threads, Mutexes und Monitore uchar.h Unterstützung für UTF-16- und UTF-32-kodierte Unicode-Zeichen

Yeah it's C99 like long long - that's why I wonder how to declare 64-bit integer in ANSI C/C89/90 :/

Yeah it's C99 like long long - that's why I wonder how to declare 64-bit integer in ANSI C/C89/90 :/

Well look up ilp64

I think the default for most is lp64

Which states that long and pointer are promoted to 64-bit and integer is 32-bit

BTW do remember that int* is usually 64-bit and int is usually 32-bit All pointers usually have the same size but this is not strictly a requirement per ISO

Otherwise the quickest way is to just use a long

Yeah it's C99 like long long - that's why I wonder how to declare 64-bit integer in ANSI C/C89/90 :/

switch to Ada 🏃

Lol

Otherwise the quickest way is to just use a long

But I need to make sure it's at least 64-bit

Is there really no portable way?! Did ANSI C had no 64-bit integers?!

Do you have to stick to ansi C? C99 is pretty supported ob most if not all platforms

Do you have to stick to ansi C? C99 is pretty supported ob most if not all platforms

Yes :( like you said it's not supported an ALL platforms and I really need all :P

I think it's just weird that there is no long long in ANSI C and long is 32-bit?!!

Maybe I should just use C++

Or C99...

But I think it's stupid they made long 4 bytes even when remains from 16-bit systems. I mean it just makes more sence to have short 2 bytes, int 4 and long 8...

I just read it looks like MSVC is not supporting C99 at all :( so I need to use good old ANSI C

Yes :( like you said it's not supported an ALL platforms and I really need all :P

You have to use preprocessor to typedef int64 for all compilers you care of then

okay... I will search for some code

When your code doesn't work😂

When your code doesn't work😂

Or when you see there is no 64-bit int in ANSIC C

I wonder what standart the linux kernel follows ....

Because AFAIK it has 64-bit ints

Really? I mean of course that's possible - but will the compiler use the 64-bit registers (rax, rbx, etc) for my own 64-bit types?! And since I can't overload operators I will have to write a lot of ugly macros or inline functions

Maybe I should just use assembly 😡

Ahh I think I will just use C99... I mean I can compile on windows with clang... and it has SOME support of C99 :)

msvc also has some 99 support

Why use C89 or C99 while there are newer standards?

long long at least

Why use C89 or C99 while there are newer standards?

To be full cross platform - C99 is well supported but C11 not that...

msvc also has some 99 support

Yes but for example they just didnt include the restrict keyword so you have to do a #define restrict __restrict there :(

Yeah you are right - I think I will go for C99 now. Or just ignore all that cross platform stuff and go with C++

or Rust - but for very low level stuff C still feels better for me - Rust is not that transparent there

I was debugging my code and the debugger is showing this. Can't understand what does the exception at the start of function mean?

I was debugging my code and the debugger is showing this. Can't understand what does the exception at the start of function mean?

It's probably the size of your array

The correct way to allocate such huge structures is to call malloc

And check if the allocation actually succeeded

3*1e7 is approx 120 MB, shouldn't the os have allowed that much stack space?

3*1e7 is approx 120 MB, shouldn't the os have allowed that much stack space?

No

is there a way to know how much space is allowed for my array size?

hmm makes sense

is there a way to know how much space is allowed for my array size?

No

That is heavily dependent on the compiler and the environment it is compiled with

is anyone here preparing for GATE2021 message me privately

is anyone here preparing for GATE2021 message me privately

Wrong group

That is heavily dependent on the compiler and the environment it is compiled with

ok, Thank you very much.

ok, Thank you very much.

Just use malloc

ok

Just use malloc

vector<int> should work fine, right ?bcz of dynamic allocation

Sorry no idea about C++

BTW, this int *arr = new int[SIZE]() ; allocates SIZE no. of ints, with value-initialise with 0, didn't they provide a way to initialise it with some other value as in case of vector<int> arr(SIZE, value)?

hmm

BTW, this int *arr = new int[SIZE]() ; allocates SIZE no. of ints, with value-initialise with 0, didn't they provide a way to initialise it with some other value as in case of vector<int> arr(SIZE, value)?

A simple loop should be eligible to initialize this. Do you have any objection to use it?

A simple loop should be eligible to initialize this. Do you have any objection to use it?

yeah, that will, BTW, is there any slowness in the manner the way vector<int> arr(n, value) will initialise it as compared to loops?

yeah, that will, BTW, is there any slowness in the manner the way vector<int> arr(n, value) will initialise it as compared to loops?

I think memset will do the same.

I think memset will do the same.

i think no

i think no

Why?

It byte-initialises the memory

Oh right.

Memset just sets every byte in a region of memory to a particular value.

is anyone here preparing for GATE2021 message me privately

why?

anyone?

this. @ammarfaizi2

since, globals are stored in data-segment, is there a particular size for this too? like that in case of stacks

yeah, are such kind of functions in c++ just provided to save the programmer from writing manual loops?

this. @ammarfaizi2

Yeah, it is probably better to use a simple loop at the moment, other than looking for something that we don't even know it exists.