I want to find all instances of a substring mysub in array container myarr and replace each occurrence of mysub with empty string " ". To do that, I'd like to use for loop with search algorithm.
Code below:
p=array iterator
for ( p=search(myarr.cbegin(),myarr.end(), mysub.begin(),mysub.end();
p!=myarr.end();
p=search(p,myarr.end(),mysub.begin(),mysub.end() ); {
[Code] ......
Is there an algorithm in the STL to move elements similar to how std::copy works? I have read various places that the new C++ standard has a move algorithm. Unfortunately the compiler I use (g++ (GCC) 4.2.0) does not support any C++0x updates.
I have a std::deque that I want to move a range from into an array. I am currently using something like this where
data_array is an unsigned char pointer to a buffer being passed in by the caller
dataQ is a std::deque<unsigned char> that is a member variable maintained within the class
Code:
for (int i = 0; i < numberBytesRequested; ++i) {
data_array[i] = dataQ.front();
dataQ.pop_front();
}
I'm concerned that executing this loop over and over again is going to be very inefficient.
I need to create an array container with the same structure as double myA [100][100];. But I cannot declare it as array<double, 100, 100> myA; however I do need this container for its format. How can I make it work.
View 6 Replies View RelatedI am trying to pass a 2D array called f (coming from a text file with 9 columns of numbers and 297,680 rows) that was created using the vector container in my main() to the function myfunc. I'm just trying to figure out how to pass the address of f in main() to myfunc(), so that myfunc() has arguments consisting of a pointer g (that accepts the address of f as an input) and an int.
This is the error from the compiler:
test_2d.cc: In function ‘int main()’:
test_2d.cc:47:25: error: cannot convert ‘std::vector<std::vector<double> >*’ to ‘double (*)[297680][9]’ for argument ‘1’ to ‘int myfunc(double (*)[297680][9], int)’
return myfunc(&f,count);
^
Here is my code:
#include <iostream>
#include <fstream>
#include <iomanip> //allow setprecision to get all the decimal points
#include <vector>
#include <string>
[Code] ...
Assume you want to use a loop to process an array of characters starting from the beginning of the array. You want the loop to stop when you read the null terminator character from the array. Fill in the loop test condition that will make this work correctly.
index = 0;
ch = array[index];
while ( _____________________________)
{
// process the character
index++;
ch = array[index];
}
So I'm writing an RPG and I'm in need of an inventory system. Of course as an relatively old member of the forum I know best than just come here and ask so I've already researched quite a bit and I've formulated this idea.
I've kind of conceptualized it like so: I'll have some sort of STL container of a unique_ptr of my base item class. There will be derived item classes. Taking advantage of polymorphism I can then call the new Derivedclass when inserting it in the STL container.
My questions are: What STL container should be used for the inventory(fixed sized)?
What is container class? what its advantage ?
View 2 Replies View RelatedI have a pile of data, which i need to access frequently and fast. One entry consists of two unsigned ints, let`s call them source and destination.
One source can have several destinations, but this rarely ever happens. Several sources can have the same destination - this happens more frequently, but still scarcely.
Once the data is set up, it rarely ever changes - yet it should be possible to add or remove entries.
I now need to find all sources for a given destination, or all destinations for a given source.
The question: which stl container to choose?
I have tried a multimap, using the source as key. This works good for finding all d for a given s, but is inefficient in the other direction.
Do you think it would be more efficient to have two multimaps, sorted respectively by source and destination?
I have two variables t and x in an array that alternate. I want to add two t's and find the average and then do the same for the x's. After that, I want to find the slope of x -> t. My problem is that I specify the n for t, but since it's local I can;t use it for the slope. Here's my code so far:
#include <iostream>
using namespace std;
int main() {
double PA [8] = {0.0001234, 1.0005434, 0.0005678, 1.0023423, 0.00063452, 1.0001546, 0.00074321, 1.00017654};
[Code] ....
And, can I actually use the n2 as an index, or will the processor not understand that?
I am trying to come up with a way to make use of a "multilevel dynamic" container. I am parsing a file to grab some pieces of data. Lets say the first field of data I find I push into an array. At the same time lets I wish to create 2 cascaded sublevels. So an element in Modules is a pointer to the Types vector associated with that module and each element in Types is a pointer to a vector of Data. This concept should be similar to memory paging.
/*
Modules Types Data
____ _____ ______
|____|------> |_____| ---------->|______|
|____| |_____| |______|
|____| |_____| |______|
|____|
|____|
|____| _____ ______
|____|------> |_____|----------->|______|
|____| |_____| |______|
*/
Obviously this becomes very hair quickly so it is obvious that I need to dynamically create and destroy vectors (if I do it this way). Should I just create pointers using the new operator?
Here is some of my code if it is even worthwhile to read:
class Parser {
//storage arrays
vector <string> modules;
vector <string> terminal_type;
vector <string> tag_type;
vector <string> data;
[Code] ....
parse this stuff and nicely organize it.
If you take the first one, "max_logvar" is a module so everything between < and > is associated with that module.
symb is unimportant for now.
then "proterm" is a "module type" so then module now needs a module type container but I may have more than one of those.
so then I break it down by "Input" and "Output" where each of those can have the integer values (just in an array where each position will be set) that are in the fields to the right.
I have a container in c++11 and i must delete first object and i don't know how...
for (const prob& p : *static_cast<vector<prob>*>(list.listData)){
// i must delete the first object
}
How do we design a container of objects all of which belong to some subclass which directly/indirectly inherits from a given parent class? Moreover, I would like to have functions that enable me to pick only objects of a certain class type from the container.
For example if the parent class is A and I have a hierarchy of classes that derive from it, we must have a container that can contain any class that exists in this hierarchy. Also, get_B() must be able to let me examine only those objects in this container that inherit (directly/indirectly) from class B (class B exists in the hierarchy rooted at A).
Preferably, we would like to avoid downcasting. Or even explicit typechecking of any sort.
To my understanding, a Container should have an Allocator member data, which is used internally.
Question: what happens, for example, when we swap() two containers that use different allocators?
Must the allocators be swapped as well?
Must all elements of the container be reallocated when the allocator is changed?
I know that it's a class that contains data from another class I just do not know how to make them both work together.
View 1 Replies View Relatedi built a programming language called jade that right now can only print. i want to add variables to it however. I am going to use a modified bajarne stroustrop calculator to handle expressions (ie will now include string manipulations and such), but I want to build a var class into the program to make it easier for the program. i want variables to act like python variabes, and arrays to act like python associative arrays. Ive scoured different containers, but they only work if the variable isnt an array in my language, because it will only have one type. the only thing i can come up with is a union and 4 overloaded = operators (for bool, int, double, and string) is there a better way to do this?
View 2 Replies View Relatedso i have a container called Source that is of type std::map<std::string, std::vector<std::string>> but when I try to print it with this function:
void Lexer::PrintSource()
{
for(auto Iterator = this->Source.begin(); Iterator != this->Source.end(); Iterator++)
for(auto SubIterator = Iterator->begin(); SubIterator != Iterator->end(); SubIterator++)
cout<< *SubIterator << endl;
}
i get these errors:
Lexer.cpp: In member function 'void Lexer::PrintSource()':
Lexer.cpp:29:42: error: 'struct std::pair<const std::basic_string<char>, std::vector<std::basic_string<char> > >' has no member named 'begin'
for(auto SubIterator = Iterator->begin(); SubIterator != Iterator->end(); SubIterator++)
^
Lexer.cpp:29:76: error: 'struct std::pair<const std::basic_string<char>, std::vector<std::basic_string<char> > >' has no member named 'end'
for(auto SubIterator = Iterator->begin(); SubIterator != Iterator->end(); SubIterator++)
^
I have a deposit of containers and i must delete the cats container. How i can do that?
#include <iostream>
#include <string>
#include <vector>
using namespace std;
struct Cat {
string name;
int age;
[Code] .....
I need a "meaningful" way of accessing a table, the column is representing Err magnitude, and the row is representing Rate magnitude. For each error magnitude and rate magnitude, i define an action magnitude, which is the contains of the table. For example,
Code:
int matrix[10][10];
int Action1 = matrix[0][0];
int Action2 = matrix[0][1];
However, i need a better way of getting matrix[0][0], row and col itself is meaningless. I want to access the table like
"Action magnitude" = matrix["Rate magnitude 1"]["Err magnitude 2"]; using a string instead of int id.
How to easily do this in c++ container?
I have a class called CTestObject and it has one variable int id. I want to add instances of this to an std container and be able to:
1. quickly determine if the value of "int id" exists in the container and update the object
or
2. add a new object to the container
Which std container is the best for this application? What method should I use to search the container for the object id?
How do you find, when you first introduced with say some of the STL container, function or algorithms, what are its requirements? I mean,
1. what operators object should have for specific container?
2. what function args and type it should return for a algo?
3. when extending some container like with custom allocator, char_traits...and what not, what methods should be overridden? What work should they do?
When using an iterator with a std container (list / vector etc) sometimes it's possible to modify the container (e.g. delete an item) yet still carry on using the iterator - whereas in other cases, modifying the container immediately invalidates any open iterators on it. Is there an easy way to know which containers fall into which category? (or does it vary from one compiler to another?)
View 2 Replies View RelatedI'm having trouble figuring out how to calculate the sum of two lines in the array(for loop)? And the next part, I can return the values to the main program however, how do I do it with c pointers?
(1) Write a C function that takes an integer array argument. The array argument has two rows and NDATA columns where NDATA is a symbolic constant. For each column in the array argument, the function calculates the sum of the values in the first and second row. The function returns to its calling program (using a second argument and call by reference as implemented with C pointers) the maximum of these sums. Additionally the function returns the column subscript where this maximum first occurs. This subscript value is returned the usual way (using a return statement). etc...
Here is the start of the array program
Code:
#include<stdio.h>
#include<stdlib.h>
#define NDATA 5 /* define number of data per row */
int row; /* count rows */
int column; /* count columns */
[Code] ....
I am trying to unroll the inner i and j loops within this multi-dimensional array which spits out a block image. Unfortunately, the image does not match the color of the original image probably because filter->get(i,j) gets altered in a way that I don't want it to.
double
applyFilter(struct Filter *filter, cs1300bmp *input, cs1300bmp *output) {
long long cycStart, cycStop;
cycStart = rdtscll();
output -> width = input -> width;
output -> height = input -> height;
[code]....
I'm taking an intro to programming course and my assignment is to Write a very simple program that uses two for loops and ONLY pointers and pointer arithmetic (NO other variables are allowed) to display a palindrome forward then backward. Declare the palindrome as follows: char str[] = “Straw Warts”; Well my prof never did anything with char arrays and I can't quite fit make the pointers work in the loop. This is my code. It runs how it should, i just can't seem to make a working for loop. It always says that you can compare int and char
#include <iostream>
using namespace std;
int main()
{
[Code]......
How to write a program without using any type of container .
View 4 Replies View RelatedI'm having trouble understanding on how to actually store into a container from another class. Any simple example.
View 9 Replies View Related
