i want to assign number of bits by a variable in bitset? how to do that? like bitset<4> foo; instead of 4 i want to use some variable and later on by user i want to assign it! boost library or any other library!
View 1 RepliesI am writing a math program, using variables of type double, and had initialized all variables to 0.0.
I now realize that not all results will be valid.
Is there a way to explicitly assign a variable of type double a non-numeric value, for example, "NaN", "Undefined", or "Unassigned" or something like that?
That way, when I read through the printout of results, I will realize the "NaN" results indicate a valid solution was not found. Whereas a 0.0 might not stand out.
I'd hate to have to go back and delete the initialization, and then re-assign 998 values just for the sake of 2 non-solutions.
I am working on a project where I need to retrive a double number and store 8 bits of the number in one field and the other 16 bits in another field. the code below gives me an error.
lata= lat>>8;
latb = (lat & 0xff);
The error states that & and >> are illegal for double. With this in mind, can I use these on a double. If not what can I do to achieve what I am trying to do?
I've been experimenting with pointers and am getting the below error.
'error: cannot convert 'int**' to 'int*' in assignment'
I thought it was ok to assign a variable address to another variable. Line 18 is where I get the error.
I am trying to show the progression of memory as I increment it as I have done on line 17 and again, I don't know why I don't see a progression through memory locations when output to the console on line 20.
Here's the code:
#include <iostream>
#include <cstring>
#include <cstdlib>
using namespace std;
int main() {
int *tt = new int;
int *p = new int;
[Code] .....
Im starting with C. Like I said in the title, how do I assign the value from a function to a variable? I mean I have this function:
Code:
int EnteroAleatorio(){
rand();
return rand();
}
and I would like to assign the value of EnteroAleatorio to a variable in my main function, but when I try to do it and compile, I got the next error: non-lvalue in assignment
I have to ask system (linux) for a value and then assign it to the variable.
Example:
unsigned char date[] = system("date");
Of course this is wrong, but illustrated what is my goal.
How to achieve this effect ? I've heard about POSIX but how to include and use it.
What I'm trying to do is to assign the length of a string to an integer variable. This is what i tried, it did not work.
Code:
printf("Enter a string
");
fgets(test_pass, 30, stdin);
strcpy(x,(strlen(test_pass)));
printf("%d", x);
This was just a test, and it did not compile. How to do this?
I am trying to retrieve the first three bits of a number. The code that I am using should work but it isn't giving me the correct result when trying certain numbers. Below is the code I am using:
unsigned short num1, num2 = 0;
unsigned short num = 65535// binary 111111111111111
num1 = num && 0x07;// gives me 1 but should give 7(111)
num2 = num >>3;//gives me 8191, which is correct
Why I am not getting the first three correct bits(111)?
I am working on a project where I need to reverse bits for a number.
For example, if I have 110111100000000 I need to reverse it to 0000000001111011.
what I need is to get the first integer from a file and assign it to a variable and the others integers to an array. Example: Thats my file content 5 4 6 7 8 0 and that would be the code:
Code:
struct Array{
int n;
int *v;
}
[code]....
I have a 64-bit uint64_t number:
Code:
Primitive<uint64_t> b = 0xCCCCCCCC00000000; I need to save the first 31 (most important) bits - 7FFFFFFE.
I found this solution in the Internet:
Code:
start = (((b)>>(first)) & ((1<<(((last+1)-(first))))-1)); but in my case for this code:
Code: Primitive<uint64_t> start = (((b)>>(32)) & ((1<<(((63+1)-(32))))-1));
I get an error: left shift count >= width of type
And even if I change 63 to 62:
Code:
Primitive<uint64_t> start = (((b)>>(32)) & ((1<<(((62+1)-(32))))-1));
I get: error: integer overflow in expression
The task is to return the number of bits set to true.Here is my code:
Code:
int cardinalityBS(PBitSet _this) {
int s, counter = 0;
for(s = 0; s < 31; s++) {
counter += _this->bits & 1;
_this->bits <<= 1;
}
return counter;
}
[code]....
The code is not working, since whenever I set _this->bits to a number, it returns me the wrong result.
how to show all the bits of a number using bitwise shift operator....and hence represent the number in 2's complement representation
View 1 Replies View RelatedThis code gets a binary number and change its bits. I have a problem with the "bits_up" function . Why this function not working?
Code:
#include <stdio.h>
#include <stdlib.h>
int bits_up(uint first,uint last,int *ptr);
int main(void)
{
uint first,last,bitUD;
int InputBinNumber[4],updatedNum[4];
[Code] ....
I have this simple program below:
Code:
#include <stdio.h>
#include <limits.h>
unsigned int rightrot(unsigned int x, unsigned int n) {
/* calculate number of bits in type */
size_t s = sizeof(x) * CHAR_BIT;
[Code] ....
The result it prints is 2684356604 on my 32-bit computer. The result I expect is as follows:
0xFF94 is 0000000000000000 1111111110010100 in binary.
Shift it right by 5:
0000000000000000 0000011111111100
Then take that result in shift it right by 27 (s is 32 and p is 5, so the difference is 27):
1111111110000000 0000000000000000
Now we use bitwise or:
0000000000000000 0000011111111100 | 1111111110000000 0000000000000000 = 1111111110000000 0000011111111100
That in decimal is 4286580732. So how does it come up with 2684356604?
I have a string - a whole sentence that I want to assign a number to each letter, space, comma and period etc. So all "A's" will have the same number, all "B's" will have another number etc. I don't want to use the ASCII numbers because they all need to be sequential and some of the punctuation isn't. I have put the string into a char array to separate each character out and was thinking about running it through a loop with if statements for each letter and assigning numbers there and then saving the numbers in the order they appear into a list as a string but I keep coming up with errors so I don't know how to do it or if there is a better way to accomplish what I'm trying to do.
View 1 Replies View RelatedI am looking to have a member of type bitset in a C++ class. Is it possible ?
Something like below:
Class abc
{
bitset<32> var;
}
I've got some problems with the declaration of a bitset container in my class
I've got a class A and want to have a bitset container in it, whose size just get's defined when running an instance of this class:
#include <bitset>
class A {
bitset <n> bc;
A(int n) : n(n) {};
};
Something like that.
I am designing an application in which I need to deal with many different variables in which different sequences of bits are stored. I have very strict memory requirements so I decided to use the boost::dynamic_bitset data type which works very well in my scenario as I need to dynamically allocate/deallocate/resize the variables.
The only problem is that I am not able to change the size of the blocks in which the dynamic_bitsets are stored.
I mean, even if I specify the blocks should be "unsigned char", I always obtain 32 bytes allocation by sizeof function, even if the variable is empty.
So I have a template, part of a larger code, that is designed to calculate the number of multiplications it took to reach a certain number. The problem is, whenever I execute the program, mults is always printing out a strange number, perhaps its actual address.
template <class T>
T power3(T x, unsigned int n, unsigned int& mults) {
if (n == 0) return 1;
if (n == 1) return x;
if (n == 2){
[Code] ....
How do i get the fraction for any decimal number in a variable?
Code: Code: #include<iostream>
using namespace std;
int main()
{
double x = 1/6;
cout << x;
cin.get();
}
In C how can I initialize a variable that is not a letter or number? For example with a number I can :
Code:
int i = 5;
for ( i = 0; i <=5; i++ );
printf( "%d", i ) This would display a row of 5's
but what if I wanted to display a row of -----? What I am trying to do is read in a simple txt file, around the file I want ----1----2-----3 ect ect on the top ----a----b-----c down the side Then I want to be able to change the file at lets say position c2 and save it. This is the early stages of my attempt to set up a editable table.
Write a function write with variable number of arguments that takes a string first argument followed by any number of arguments of type double and prints on the screen a string formatted by the rules described below. The first argument may contain formats in curly braces of the form {index[:specifier]}, where the square brackets show optional parts (this is :specifier may be missing), and index is the sequence number of an argument of type double (starting from sequence number 0).
Rules for formatting: In the printed string the curly brackets and their content will be replaced by the argument with the given index, formatted according to the given format specifier. If the format specifier is missing, the argument will be printed with its default format. For example:
write("The number {0} is greater than {1}.", 5, -3);
will print
The number 5 is greater than -3.
write("There are no format specifiers here.");
will print
There are no format specifiers here.
The format specifiers and their meanings are listed in the following table
Specifier MeaningFormat Output for 1.62 Output for 2.0
none default {0}1.62 2
ccurrency{0:c}$1.62 $2.00
escientific{0:e}1.620000e+000 2.000000e+000
ffixed point{0:f}1.620000 2.000000
iround to int{0:i}2 2
Limitations: You may limit the maximum number of arguments your function can process to a certain value, for example 10.
Suggested extensions:
-Add an optional alignment specification in the format , e.g., make the format of the form {index[,alignment][:specifier]}, where alignment is an integer specifying the width of the field in which the corresponding argument will be printed. If alignment is positive, align to the right, if it is negative, align to the left.
-Accept an optional integer after the specifier letter, specifying the required precision in the output. For example, {0:f2} will print the number 1.6234 as 1.62, but {0:f5} will print it as 1.62340.
Im having trouble on getting the quantity up of the variable "item.iqty". For example the current quantity is 5 and in this function, the user inputs a number and it should add to the variable "item.iqty". So if if the user inputs 2 then the current quantity should be 7 now but in my program it hasnt changed. its still 5
void addQty(FILE *fp)
{
int num, qty, r, c, n;
bool found;
[Code]....
I'm a basic C++ programmer, and I am stuck on this problem. You work for a company that collects a set of numbers. The numbers are located in a data file named "./Data_File". The data file contains two columns. how do you count a certain number on the left column.
#include <iostream>
#include <fstream>
#include <cstdlib>
#include <iomanip>
using namespace std;
#define DATA_FILE1 "./Data_File"
#define SUCEESS 0
#define FAIL 1
[code].....
how to make a program in which a user is prompted to input four numbers like 1234 and then print those four numbers one by one on screen using only one variable..??
For example:
1
2
3
4
in ascending order...
I've done that with two methods but i am not sure whether the methods were correct..