Is it possible to write a program such that it will automatically execute the function in queue base on their priority even if user programmed it randomly?
Code:
function1(){ very_important; }
function2(){ important; }
function3(){ less_important; }
int main() { // Programmed by user
function3;
function1;
function2;
//Output: Program will execute function1, 2 and lastly 3.
}
For easier debugging, I would like to execute an own (predefined) function while beeing in a breakpoint (e.g. print some variables to a file).
Does there exists such a feature?
e.g.
- run program to a breakpoint
- a) press a keyboard-function-key (which calls that predefined function)
- b) or hover with cursor over a variable (and modify somehow the routine which shows its content on the screen)?
I have simple LCd_call function . I am calling this function from main . I wanted to call this function once. problem i am facing here, When lcd_call function being called. It enter the cases but instead of staying paricular case it coming back and starting case 1 iteslf . for every 6s it change the case to 1:
View 2 Replies View RelatedI would like to implements something in my code that clears the value of my variables when the user closes the console. How to do that or the program clears the values automatically?
View 3 Replies View RelatedI know how to use functions pointers in C and C++ and I know if you have something like
char buf[] = {
0x48, 0xb8, 0x3c, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x48, 0xbf, 0x02, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x0f, 0x05
};
((void (*) (void))buf)();
That this will execute those binary instructions in hexadecimal notation BUT WHY? I don't get why that works since that's an array of data not a function?
I wish to add the item 'Website' to an MFC Dialog app System Menu so that it can activate the following method:
Code:
void CMyDlg::OnWebpage()
{
ShellExecute( NULL, NULL, _T("[URL]..."), NULL, NULL, 0 );
}// OnWebpage()
I have tried this:
Code:
#define IDM_WEBSITE (WM_USER + 101)
//..
if (!strAboutMenu.IsEmpty())
{
pSysMenu->AppendMenu(MF_SEPARATOR);
pSysMenu->AppendMenu(MF_STRING, IDM_ABOUTBOX, strAboutMenu);
pSysMenu->AppendMenuW(MF_STRING, IDM_WEBSITE, _T("Website"));
}
[Code]...
The code compiles without error but and the 'website' item appears on the System Menu but it doesnt do anything.
I've inspected the following but don't really understand how it works and it seems to me there should be a simpler way to accomplish my end.
Modifying the System Menu By John Simmons 26 Jan 2007 [URL]....
How to build a FiFO queue without using the STL (done that no problem), get it to dequeue (again, done that no problem). However, to get those extra marks, I need to be able to order it using a priority system.
I've tried ordering the NodeDequeue class that I'll show at the bottom of this post, but I just cannot get it to order appropriately. The closest I have got is everything in order but I lose a Node from the memory completely. So, that's no good.
The most logical idea I have thought of right now is to send the largest number to the back of the queue each time it's iterated, eventually, the largest number will end up at the front.
class PriorityQueue : public Queue {
public:
Node* NodeDequeue(void) {
Node* tmp = front;
Node* seek = tmp->getPrev();
[Code] .....
I'm trying to implement Prim's Algorithm and for that I need to have a decreaseKey method for a priority queue (to update the key value in a priority queue). Can I implement this in the STL Priority Queue?
This is the algorithm I'm following:
for each vertex u in graph G
set key of u to INFINITY
set parent of u to NIL
set key of source vertex to 0
en-queue to priority queue Q all vertices in graph
[Code] .....
I've got a priority queue of items who, from time to time, returns a different comparison result. Any way to re-sort a priority queue who is storing them?
Example:
#include <cstdlib>
struct Random {
bool operator<(const Random&) const { return !(rand()&1); } };
I have created a string array of 5 and I will use that to enter some "tasks", then I also have an integer array of 5 where i can assign priorities to the information in the string
string info[5];
int p[5];
cout<<"Enter info 1"<<endl;
cin>>info[0];
cout<<"Enter priority"<<endl;
cin>>p[0];
etc,
I want to be able to link the priorities that i assign to that string and be able to call the information that has the highest priority. I can only using iostream and string header files so far,
how double ended priority queue be used to implement external quick sort?
View 8 Replies View RelatedI know queue but with priority queue i am really amateur. How to implement some functions in priority queue.
template <class T> class PRIORITY_QUEUE {
private:
T *items; // array of queue items
int rear;
int maxSize; // maximum size of queue
[Code] ....
and what does heapify mean???
quishing some bugs, and also how to go about squishing these bugs?
#include "stdafx.h"
#include<stdio.h>
#include<malloc.h>
[Code].....
Here are the errors after compiling the program.
write a program, pfpq.c, that maintains a priority queue of music tracks (songs) and ratings. The struct is given by:
Code:
struct track
{
char artist[20];
char title[20];
int rating;
};
The program is only designed to demonstrate the concept so get the user to enter a small number of tracks and create a priority queue. (Use an empty string title or an empty string artist to end the program). Print the priority queue as it grows. Your program should initially ask the user if they wish to order the priority queue by rating in ascending order, or by rating in descending order, or if they wish to order the priority queue by artist name. Then build the priority queue accordingly. in the last case, "if they wish to order the priority queue by artist name." which is case 3. How do I sort the priority queue by artist name using in the following code.
Code:
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "pqueue.h"
struct track
{
char artist[20];
char title[20];
int rating;
}
[code]....
i am working on creating a priority queue, i seem to have done the algorithm for inserting from the top correctly but the algorithm for inserting from the bottom doesnt seem to work it just overwrites the existing data.
below is my code :
list is an array and listlength is the size of the array declared as a integer
void inserttop(string task) {
//int head = 0 ;
string temp ;
listlength++ ;
for (int i = 1; i < listlength; i++) {
[Code]...
So i have been banging my head against a wall with this problem for awhile. I have also copy and pasted direct examples from the internet but nothing seems to sort it right.
Node Header
Code:
#ifndef _NODE_H
#define _NODE_H
#include <stdio.h>
class Node {
public:
Node();
Node(int weight, char value, Node* left = NULL, Node* right = NULL);
[Code] ....
On several occasions in my project, I need to sort elements (indeces) based on their linked values. Those values are stored in an array. This means the comparison looks like this:
bool operator()(int i, int j) { return someArray[i] > someArray[j]; }
Because this form returns often but someArray may differ, I wrapped this in a template class:
template<class T>
struct sorter {
std::vector<T>& data;
sorter(std::vector<T>& __d) : data(__d) {}
bool operator()(int i, int j) const { return data[i] > data[j]; }
};
Now, I want to use this in a different way: I want to select the K indeces with the lowest value from someArray attached to it. My idea was to build a priority_queue, push the first K elements and then compare all the next elements to PQ.top(), as such:
INDEX t(0);
for (; t < someLimit; ++t) {
pq.push(t);
if (pq.size() == K) break;
}
for (; t < someLimit; ++t) {
if (someArray[t] < someArray[pq.top()]) { pq.pop(); pq.push(t); }
}
My problem, however, is the definition / initialization of the priority_queue object. My first idea was simply std::priority_queue<INDEX> pq(sorter<VALUE>(someArray));, but calling any function on pq provides the error "expression must have class type" (?) when hovering over pq.
My second guess, std::priority_queue<INDEX, std::vector<INDEX>, sorter<VALUE>(someArray)> pq;, provides the error 'expected a ')'' when hovering over someArray.
What is the correct way to initialize this data structure?
This assignment is about Heap and PQ's to sort out jobs inside a printer. I'm far from finishing the assignment but the most important part isn't working. My issue is that nothing is getting stored inside the array. I keep getting crashes and at this point I'm not sure what to do. I notice that my destructor runs right after my "addJob" Function finishes, which is destroying the memory. Which might be why nothing gets stored inside OR I think my implementation of Heap/PQ is wrong.
Functions inside my test.cpp aren't properly done, they are made just to see if something is stored inside.
1. Check if I created the array correctly [PQtype.cpp / Heap.h/ PQType.h]
2. Am I even using/storing into the array. [Test.cpp "addJob" Function]
3. I'm also new to working with Class Templates.
PQType.h
template<class ItemType>
class PQType {
public:
PQType(int);
PQType(const PQType&); /
[Code] .....
There appears to be some kind of error in by removeMin() function. Inserting items seems to work just fine but attempting to remove any items gives me the error "vector subscript out of range".
Here is my SortedPQ class... Below it you will find the quicksort implementation, in case looking at it is necessary.
template <class Type>
class SortedPQ {
private:
int front;
int rear;
vector<Type> V;
public:
SortedPQ(void) : front(-1), rear(-1), V(0){}
[Code] ....
I've got 2 classes, Store and Transaction and I would like to create a priority queue of objects Transaction as a variable of Store class.
My store.h
#ifndef __STORE_H_INCLUDED__
#define __STORE_H_INCLUDED__
#include <queue>
using namespace std;
#include "Transaction.h"
struct TransactionCompare;
[Code] ....
The error im getting with this set up is
error C2664: 'bool TransactionCompare::operator ()(const Transaction &,const Transaction &)
const' : cannot convert parameter 1 from 'Transaction *' to 'const Transaction &'
I'm trying to use a priority queue sorting in reverse order to take a vector or 2d array. The problem is that I want to sort by the vector/array cell value but keep the reference to the vector/array index of the value. I don't know quite howto keep them both related so when I pop. I can find the corresponding cell.
priority_queue<int, vector<int>, greater<int> > Open;
I'm the author of a realtime MIDI software called ChordEase which makes use of the MIDI aspects of the multimedia API, specifically MIDI input callbacks. In XP and before, these callbacks originated in the kernel and therefore had realtime priority by definition, but from Vista on, they originate in thread pool threads, and have a priority of zero. This is a problem because at priority zero they can be blocked by the GUI thread, causing serious latency, and I have proved that such blocking occurs.
I have experimented with raising the callback thread priority, using either of the following methods: 1) calling SetThreadPriority within the MIDI input callback function, and then setting a flag so that it isn't done repeatedly, or 2) creating a DLL that catches thread creation via DLL_ATTACH_THREAD in DllMain, and calling SetThreadPriority there. The first method is slightly wasteful since the flag has to be tested for every MIDI input event, but it also has the advantage of only affecting the MIDI input threads, whereas the second method affects all threads in the pool regardless of what they're used for. Neither method appears to cause any harmful effects but they make me nervous*. Other possible methods would include 3) using the thread pool API to raise the priority of the pool (assuming I could gain access to the pool handle somehow), or 4) permanently lowering the priority of the GUI thread, which I'm very reluctant to do because of the risk of unintended consequences.
I'm assuming the MIDI input callbacks are using threads in the default thread pool though I haven't actually proved this. Assuming that's so, are these threads private to my application, or is my application sharing them with other applications? Is there a safer way to achieve the result of increasing the priority of MIDI input callbacks? It's incredibly frustrating that MS would change the behavior of MIDI input callbacks so drastically without even telling anyone, but that's how it goes!
[URL] ....
*See for example theses warnings about changing thread pool priorities : [URL] ....
I compiled/built a code I had and made an executed file but when i click on it the CMD closes instantly. Is there anyway to keep this open?
View 10 Replies View Relatedi need to create an small windows form, with some buttons, and then those buttons will "exectute" an action on a remote webserver.
Im searching with http requestings and didn't find nothing useful for what i need.
The basic thing is that i just need to press "EXECUTE" and then c# will press one link in the Webserver. I do not need any feedback from the page. I just need that C# execute a link like localhost/startbackup.php then the actions from the startbackup.php will run.
I do not need any information regarding if the page was successful executed or not, or even if it opens one window. Nothing.
I'm wondering whether it's possible to implement MPI to execute a process in parallel from deep within a C++ solution.
I've created a solution on VS2005 that links to several static libraries, and within one of these libraries there is a set series of tasks that require execution many times - they're independent so I'd like them to execute them using MPI if possible to speed up the run time.
The pseudo-code is:
Code:
for(i = 0; i < n; i++) // n is number of times to execute process {
PerformTask(data[i]); // perform the tasks required for each iteration of process
}
So, instead of conducting the tasks within PerformTask() in series n times, I want to split the array data between multiple processes such that they can each be allocated an even proportion of data to perform the tasks on. Pretty textbook reason for wanting MPI, right?
Now, I've read up and understood the basics of MPI implementation, but all the examples I've seen are called within the main() function of the program. But I need to do all this from within a static library, is this possible?
I've made some early attempts at implementing this, but get an error indicating the process wasn't initialised: "Error encounted before initializing MPICH", which I assumed would be due to trying to make the MPI calls outside of the main() function.
I'm new to C++ and am trying to create a program to solve the problem as described in this image: [URL] .....
Here's my code. It fails to execute the main part of the problem (years, population of A & B) but works well in recognizing errors (if PopA >PopB or if growth rate of PopA<PopB)
Code:
#include <iostream>
#include <iomanip>
#include <string>
using namespace std;
int main() {
string city1, city2;
[Code] .....