The `long long` size modifier was introduced in C++11 and can be used with integral types to select an integer of at least 64 bits.
See cppreference for more information.
Questions tagged [long-long]
131 questions
8
votes
1 answer
64 bit integers and older C++ compilers
I want to use 64 bit integers in my C++ code. I understand I can either #include and then declare a uint64_t or use unsigned long long (or the equivalent for signed versions).
However, it appears that support for this was not added until…
Simd
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8
votes
4 answers
long long vs int multiplication
Given the following snippet:
#include
typedef signed long long int64;
typedef signed int int32;
typedef signed char int8;
int main()
{
printf("%i\n", sizeof(int8));
printf("%i\n", sizeof(int32));
printf("%i\n",…
azraiyl
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7
votes
4 answers
3 * 1000000000 overflows as an int, but the variable is long long. Why?
I have a simple c++ app that performs the following calculations
long long calcOne = 3 * 100000000; // 3e8, essentially
long long calcTwo = 3 * 1000000000; // 3e9, essentially
long long calcThree = 3 * 10000000000; // 3e10, essentially
If I…
John Voss
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7
votes
1 answer
Troubling converting string to long long in C
I'm having trouble getting the atoll function to properly set a long long value in c. Here is my example:
#include
int main(void) {
char s[30] = { "115" };
long long t = atoll(s);
printf("Value is: %lld\n", t);
return…
Justin Brown
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6
votes
2 answers
cpp: eclipse doesn't recognize 'long long' type
I have some where in my code the next line:
long long maxCPUTime=4294967296;
(the largest number long type can be is 4294967296 -1 , so I used long long)
the problem is, when I compile ,I get the next error:
error: integer constant is too large…
kakush
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5
votes
3 answers
-9'223'372'036'854'775'808LL is unsigned
Since C++20 two's complement representation is the only representation allowed by the standard, with the guaranteed range from -2N-1 to +2N-1-1. So for a 64-bit signed integer type the range goes from -9'223'372'036'854'775'808 to…
user7769147
- 1,559
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5
votes
3 answers
Casting to long long (GCC)
long long x; double n;
x=long long(n);
This doesn't work. What is the correct way?
Roamer
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5
votes
1 answer
How to silence long long integer constant warning from GCC
I have some code using large integer literals as follows:
if(nanoseconds < 1'000'000'000'000)
This gives the compiler warning integer constant is too large for 'long' type [-Wlong-long]. However, if I change it to:
if(nanoseconds <…
Riot
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5
votes
2 answers
Size of "long long" in 128-bit machine?
In a 128-bit RISC-V (or other 128-bit machine), how big are "long" and "long long" data types in C/C++?
To clarify: what are the sizes that an implementer of a compiler might be expected to use when writing the limits.h file for such a machine, in…
Ivan Godard
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4
votes
2 answers
C++ Why does LLONG_MIN == -LLONG_MIN
In C++ if I do this:
__int64 var = LLONG_MIN;
__int64 var2 = -var;
cout << "var: "<< var << endl;
cout << "var2: "<< var2 << endl;
The output I get is:
var: -9223372036854775808
var2: -9223372036854775808
What is the part of the standard that…
user2672807
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3
votes
2 answers
Why would you ever add 10^9+7 to a number and then take mod with 10^9+7
I was solving a problem of Fenwick tree named shill and wave sequence and it wasn't passing all the test cases until I added a line looking at the solution and now want to find its purpose ,here is my code
#include
using namespace…
AVIRAL KHANDUJA
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3
votes
3 answers
Using preprocessing directive #define for long long
#include
using namespace std;
#define ll long long
int main() {
int a = 5;
ll maxi = 1;
maxi = max(maxi, maxi * ll(a));
cout<
coder_12
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3
votes
3 answers
grabbing upper 4 bytes of a 8 byte word
I am multiplying 0x1d400 * 0xE070381D.
When I do this on my calculator the result is 0x00019A4D26950400
When I tried implementing this in cpp here's what i have.
long long d;
d = 3765450781 * 1d400;
The result this code gives is that d =…
jprince14
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3
votes
1 answer
How to handle "type mismatch" in VBA boolean/LongLong array?
When trying to execute below code, I get the VBA error: type mismatch. Anyone know the cause (and solution? :-))
I changed datatypes from Long to LongLong to be able to handle larger numbers. Before this the code (excerpt) was working fine.
Private…
Ronald Vonk
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3
votes
2 answers
How can I declare a PtrSafe Sub in VBA? Windows 7, Excel 2016, 64-bit
I am trying to upgrade my large number VBA application from Long datatype to LongLong or LongPtr to be able to handle more digits.
But I can't figure out how to call this PtrSafe Sub... Some assistance would be very helpful.
I tried a simple example…
Ronald Vonk
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