when i was finding a way to concatenate three integers in C, I came across a snippet like this
Code:
#include<stdio.h>
#define cat(a,b,c) a##b##c
int main()
{
int d;
d=cat(1,2,3);
return 0;
}
How the macro works here? I am unable to understand the function '#' plays in the macro.
How i can concatenate two integers into one integer. I have code that concatenate two integers but if the 2nd integer is zero it won't work. How can i modify it so that it can cater the case of y=0 too.
Code:
int concatenate(int x, int y) {
int pow = 10;
while(y >= pow)
pow *= 10;
return x * pow + y;
}
Is it possible to define a macro with in a macro? Any trick will do. I am trying to do quick conversion of cuda program to open mp by defining some macros at the top:
Code:
#define __syncthreads() #pragma omp barrier
I want to concatenate string+int so i make like that
Code:
for(int i=0;i<n;i++)
{
name="obstacle"+i;
cout<<name;
}
I get in the window
obstacle
obstacl
obstac
obsta
obst
...
..
o
but i want instruction that allow me to get
obstacle0
obstacle1
obstacle2
...
This seamed as a simple thing but i am getting something i did not expect: Example:
Code:
vector<char> StrJoin(SubjSeq.size()+ QuerySeq.size());
cout << StrJoin.size()<<"
"; // size x
StrJoin.insert( StrJoin.begin(), QuerySeq.begin(), QuerySeq.end() );
StrJoin.insert( StrJoin.begin(), SubjSeq.begin(), SubjSeq.end() );
cout << StrJoin.size()<<"
"; // x*2
All structures are vector<char>. when i do the above my characters form Query and Subject are copied in my new vector called StrJoin but the size of that vector is twice the size then it should be.
Trying to concatenate the 1st and 2nd element from an array of chars. Then this to be used as a hex value.
so for example
specs[0]='f'
specs[1]='4'
concatenate_value=0xf4
I m concatenating specific range of digits that are same from an array "element" . I have problem with range. As in my case the range is col_elem[ii]=4, but it will continue reading the next element if it is the same. My code is:
Code:
int element[8]={0,1,3,3,3,0,1,2};
col_elem[ii]=4;
for (rr=0; rr<col_elem[ii];rr++){
join_tmp[qq]=rr;
while ((element[ii]== element[ii+1]) ) {
[code]....
The objective of the project is to become familiar with linked lists by writing a series of basic functions that allow us to manipulate a set of linked lists. I've completed all of the functions except for one.
The function I am stuck on is supposed to do the following:
concatenates list1 and list2 to form a new list,
and returns a pointer to this new list;
Note: new list contains copies of all nodes in list1 and list2 */
I have a function that concatenate the strings in an array(2D)
Ex 1: Sean Connery Micheal King James Wood
Result: SeanConnery MichealKing JamesWood ...
The concatenation function working correctly and displays correctly in the function. But if I make another function to display it, it shows this
Ex 2: SeanConnery Sean MichealKing Micheal JamesWood James..
It adds to first name. Why?
Code:
void Concatenation( char dest[200][13] ) {
// loop through and concatenation the strings
for(int i=0;i<200;i+=2) {
myStrCat(dest[i],dest[i+1]); // mystrcat is equalto strcat()
[Code] .....
Actually i found some mistakes in my post. So here is the modified version. I want to concatenate the indexes of elements of array that has the same value for specific range.In my case the range is 4
Code:
int element[8]={2,2,0,3,3,0,1,2};
col=4;
int rr;
int qq=0;
for (rr=0; rr<col;rr++){
join_tmp[qq]=rr;
while ((element[rr]== element[rr+1]) ) {
join_tmp[qq]= concatenate(rr+1, join_tmp[qq]);
printf("%d
",join_tmp[qq]);
rr++;
}
qq++;
}
Code:
//FUNCTION TO CONCATENATE INTEGER VALUES OF SAME GROUP IN A COLUMN
unsigned concatenate(unsigned x, unsigned y) {
unsigned pow = 10;
while(y >= pow)
pow *= 10;
return x * pow + y;
}
Code: I want input like
10
2
3
Instead i get
10
2
34
how can i fix it so it will only iterate to the specific range?
I have two std::string data items that contain binary data (so it may have the null character!). What is the proper way to concatenate them to preserve all of the data? I am guess a simple:
string string3 = string1 + string2;
Will not work, as it will terminate string3 on the first NULL character it encounters.
I'm having a really dumb moment and I cant seem to remember how an if statement works, with only the variable name as the condition..
Code:
if(var){
//then do something
}
I'm a beginner at c++ and I need to write a program that reads a set of integers and then finds and prints the sum of the even and odd integers. The program cannot tell the user how many integers to enter. I need to have separate totals for the even and odd numbers. what would I need to use so that I can read whatever number of values the user inputs and get the sum of even and odd?
View 2 Replies View RelatedI am trying to create a small set of filepath functions that I intend to compile across linux and windows (I prefer not to use a big library). I want to have a global constant PATH_SEPARATOR that depends on the OS environment. This is what I set at the top of header file.
Code:
#include <stdio.h>
const char PATH_SEPARATOR =
#ifdef _WIN32
'';
#else
'/';
#endif I was hoping to test this while compiling this in a linux environment using gcc, thusly:
Code:
int main (int argc, char const* argv[])
}
[code]....
where apparently, I seem not to be able to "set" a part of the code to have "_WIN32" defined. I don't know if I explained this clearly.
I have this macro, that expands to some methods of my class:
Code:
#define POPULAR_COMBO_FILTRO_COM_BASE(classeTabela)
void VisualizadorLogsFrame::PopularComboFiltroCom ## classeTabela (bool limparTexto) {
long from, to;
m_cbxDetalhe->GetSelection(&from, &to);
[Code]...
but I get a compile error on this line:
Code:
for (list< CLASSE_TABELA *>::iterator linha = lista->begin(); linha != lista->end(); linha++) {
what am I doing wrong ? the error is:
VisualizadorLogsMain.h:174: error: expected ';' before 'linha'
VisualizadorLogsMain.h:174: error: 'linha' was not declared in this scope
My code has been acting odd. I made a function that layers my art resources but only the last tile of my art resource acts the way it should. My character goes behind and in front of the last tile and gets printed correctly. Strangely its really exclusive to the last tiles I print. What I need is to figure out in step by step order what going on with my code sample below and be able to layer the resources.
Here is a small sample of my main function. This is how I do my rendering.
Code:
Int main (int arc, char* args[]) {
//Move class
Move character;
//Class Tile & Side Tile
Tile *tiles [TOTAL_TILES];
[Code] ......
How the getline function works.
Code:
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
int main() {
[Code] ......
getline(&inputstr, 128, NULL); getline gets a line in a data file.
I assume that inputstr[128] is the name of the file? why is the number of the array in the getline function....
This is simple recursive solution of Fibonacci number:
Code:
int fibo(int n)
{
if(n<=1)
return 1;
else
return fibo(n-1)+fibo(n-2);
}
Now the recursion will generate a large recursion tree, like if n=5, 5 will call (5-1), (5-2) or 4,3 . What I want to know is, will fibo(n-1) will be called 1st go all the way to the base case 1, then do the summation or fibo(n-2) will be called right after fibo(n-1) ?
i want to ask how does malloc works on an array for instance can i dao this
Code: p=100;
int array[10];
array = malloc(p * sizeof(int));
then will the size of int be 100 so will i be able to do like
Code:
array[11] = 12 ; ???
also if i have a 2d array how can i use malloc on it and how does this works with pointers????
I know how exception handling works, but how should I actually use it in action? Let's say I have something like this:
Class X
{
public:
X();
//Pre-condition: example can't be 3.
void number(int example);
[code]......
If I know that the exception can only happen at the beginning of the function, is it okay to catch it right away?
I have this following piece of code:
int id = 5;
const char *ptrId;
ptrId = ( int_to_str(id) ).getPtr(); // Works in Solaris well
But the above code prints some junk values when I run the same on Linux machine. But the following works well on Linux:
String temp = int_to_str(id);
ptrId = temp.getPtr();
The prototype of getPtr() is:
const char* String::getPtr() const
I'm doing right now is creating a function that callocs (I prefer this to malloc) and returns a string, and it will work similar to printf, I'm calling the function alloCpy(),I have several values that I need in a malloced string, so I call Code: myAllocedString = alloCpy("Value 1 is %s, value 2 is %s, and value 3 is %d", str1, str2, num); To do this I'm using the Variadic Macro, the reason I'm not just using a Variadic Function such as this: Code: char* alloCpy(char *format, ...) {} is because I need to append NULL to the end for the sake of looping through arguments, and I'm understanding it thusfar, but I have a few issues, first of all, I tried defining the Macro in a header file, but when I try to call it I get the error "Undefined reference to alloCpy". Also, to loop through arguments to get string lengths I'm using va_arg(args, char*) which requires all the arguments to be of type char*. Here is my code:
myheader.h:
Code:
#define alloCpy(format, ...) _alloCpy(format, ##__VA_ARGS__, NULL);
char* _alloCpy(char *format, ...); mycfile.c: Code: char* _alloCpy(char *format, ...) {
va_list args;
va_start(args, format);
int args_len = 0;
}
[code]....
So, how can I do this to, first of all, make my macro function accessible from other files importing myheader.h, and second, how can I make it accept any type of argument like printf, so that my example above would work?
Say I have something lke
Code:
#define FOO BAR
#if FOO == BAR
doX();
#else
doY();
#endif
This causes doX(); to be executed. But the intent is to have doY(); be run. I'm guessing this is because BAR is undefined and therefore blank, so blank equals blank. Is there some way to compare the symbol FOO was set to instead of its value, BAR?
I heard that const shall be preferred over #define . So I start to change my program accordingly.
But then below error message occurs during compilation:
#include "common.h"
#include "definition.h"
#include "particle.h"
int main() {
Particle *p = new Particle();
[Code] .....
I guess the error occurs because, when the line 9 of particle.h (File 4) is compiled, value of const int dimension is not seen by the compiler.
I have to migrate C++ source which is compiled with MinGW-gcc to be compiled with VS2013, and have one issue with one macro used for serialization.
Here is macro:
#define IMPLEMENT_SERIALIZE(statements)
unsigned int GetSerializeSize(int nType, int nVersion) const
{
CSerActionGetSerializeSize ser_action;
const bool fGetSize = true;
[Code] ....
Here is place in code were it is call (in class declaration):
IMPLEMENT_SERIALIZE(({
if (!fRead) {
uint64 nVal = CompressAmount(txout.nValue);
READWRITE(VARINT(nVal));
[Code] .....
When compile received errors:
main.h(555): error C2059: syntax error : '{'
main.h(555): error C2143: syntax error : missing ';' before '{'
line 555 is end of macro call ( "})").
How should look using of this macro in order to avoid that errors?
"If you examine the expansion of max, you will notice some pitfalls. The expressions are evaluated twice; this is bad if they involve side effects like increment operators or input and output. For instance, the below example will increment the larger twice."
#define max(A, B) ((A) > (B) ? (A) : (B))
max(i++, j++)/* WRONG */
I don't see what the problem is with the code above. i is incremented and j is incremented and then it performs a ternary operation to see which is greater. Am I missing something?
