I have the following map: myMap<string,vector<int>>. I now want to look through my map to see if a key exists and if it does, retrieve one of the int values from within that vector. What would be the best way to do this? Right now I have the following:
What would be the best way to look for a key and get one of the int values from its vector value? Right now I'm doing something like this:
[code]
map<string,vector<unsigned int>>::iterator it;
it = wordMap.find(someWord);
if(it == wordMap.end){
cout << "No matching entry";
} else{
// this is where I'd want to access the value (the vector) of the map
}
I have a vector that I would like to access and work with from multiple threads. I have created an example below to illustrate the functionality that I would like to accomplish.
The goals are to be (1) high speed, (2) thread safe, and (3) *if possible* continue to use vectors as my larger project uses vectors all over the place and as such I would like to maintain that.
However, if I need to switch from vectors to something else then I am open to that as well.
The following example below compiles but crashes rather quickly because it is not thread safe.
How I can fix the example below which I can then apply to my larger project?
I have a vector (structures) in a struct (instances). I make a declaration of this struct called instance. The vector is a 3-layer vector of pointers, like so:
vector < vector < vector<scene::IAnimatedMeshSceneNode*> > > structures; (The type is from Irrlicht 3D). I have 3 nested "for" loops which looks similar to the following:
for (int a = 0; a < instance.structures.size(); a++) { /*note:vector size previously set*/ for (int b = 0; b < instance.structures[a].size(); b++){ for (int c = 0; c < instance.structures[a][b].size(); c++) {
if (1) { //checking value of variable not included in snippet
These are currently referencing the pointers, it seems. The program compiles but crashes at this point. I need them to reference the values of the pointers. Problem is, I don't know where to put the dereference operator (*). Where should it go?
How to output vector contents using the push_back function. My program reads in values just fine, but it does not output anything and I've been stuck on why.
here is my code:
#include <iostream> #include <array> #include <vector> using namespace std; int duplicate( vector < int > &vector1, const int value, const int counter)
I have a cpp app that reads in a number of files and writes revised output. The app doesn't seem to be able to open a file with a ' in the file name, such as,
N,N'-dimethylethylenediamine.mol
This is the function that opens the file :
Code: // opens mol file, reads in rows to string vector and returns vector vector<string> get_mol_file(string& filePath) { vector<string> mol_file; string new_mol_line; // create an input stream and open the mol file ifstream read_mol_input; read_mol_input.open( filePath.c_str() );
[Code] ....
The path to the file is passed as a cpp string and the c version is used to open the file. Do I need to handle this as a special case? It is possible that there could be " as well, parenthesis, etc.
Here is the link for my program, I want to access the average value which is located in grade.c (calculate_grade) class through driver.c (main function) but I don't know how to make "average" visible
I came across the below code snippet in a project and was not sure how value of variable "response" is computed. Here as we can see, pic_data holds two one dimensional arrays but "response" access both the single dimensional array as two dimensional array.
I've been attempting to create a game with curses and I keep running into the problem of scope. I want to change or use variables of a different class in a different header file. But I don't know if I should use pointers, references or neither. Should I be programming in a manner that doesn't make it necessary to use variables outside of their class?
I'm currently trying to access a variable contained within a base object from another completely different object and I continually get error messages. I'll attempt to put up the important code since it's contained within fairly large classes. From the Base .cpp file. ObjectPosition:
This is the initialization function for the BaseObject. All objects are inheriting these variables which are Protected within the ObjectPosition class.Then they are initialized within the Pig class thus wise:
I have a Visual C++ solution file that contains 3 projects. i want to access the variables declared in a function in a project from a function in another project. Function declarations are in .h file and expansion in .cpp files. Can i use friend class or any other suitable method.
How do i access the private array? I tried this and it's not working. Want i want to do is create class object in main and pass the string to constructor, and set m_make, m_model to that string. Then call the member function to output that.
const int BUFLEN = 256; // class declaration class CVehicle {
I'm confused about accessing elements from arrays. Supposed I have an array of pointers to char:
char *names = { "John", "Rose", "Steven" };
To access one of the strings, should I use names[ 0 ][ i ], where i is an index in the set ( 0, 1, 2 ), or should I use names[ i ]? I would think it would be the first option, because this array has 1 dimension that contains others arrays, right?
I was wondering what the best way was to access data outside the function it was created in. I have the user input a data in a custom namespace function, and now im trying to access all those data points in a different function.
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.
I need to translate a C program to C by making variables in structures private(no classes yet!) and putting public inline functions. There's a good chance that I have much more problems with my code than I'm asking right now, but I have 4 spots that I'm currently stuck in and can't access properly.
My structures:
Code: struct Container { private: int count; char** lines; int nlines;
I want to access the elements of my array dynamically. So far I've only figured out how to do this manually. if I tried it like this my code would work but there should be a better way right?
I've recently been learning GTK (though this question is not specific to GTK), and came across a situation that I was unsure how to best handle. Essentially, I've defined several pointers in one source file, and I want to access those pointers from other source files.
The structure of my GTK programs generally follow this pattern:
- "main.c": Define the main window and run GTK main - "create_window.c": Create and arrange widget pointers in the main window - "program_functions.c": All other source code for the project (several source files in reality)
In "create_window.c", I declare and define all my widget pointers (e.g. label). If I need to modify those widgets in "program_functions.c" for any reason (say, to change the value of a label), I need access to the pointers created in "create_window.c".
My first thought was to create a global struct of pointers in "create_window.c", and extern that struct to the other source files that need access to the pointers. The thing I don't like about this approach is spreading globals across my program.
My second idea was to create access functions in "create_window.c" where the necessary pointers are statically stored. The first time I call this function (immediately after creating a widget), a static copy of that pointer is stored in the function. Each time afterwards when I call that function (from other source files), I simply use that static pointer to access the widget of interest.
