I am writing a code for Uniform Cost Search using a priority queue. I came across an error: Invalid Heap after using push function. I also tried to debug the code, but I didn't find the source of this error. Here's my code:
class Manager
{
private:
Parser *p;
Board* myBoard;
string algorithm;
string text;
unsigned int size;
stack<Brick> *myStack;
stack<Brick> *solution;
stack<Brick> *temp;
unsigned int trackCost;
set<pair<int,int>> mySet;
struct ComparatorGreaterThan {
bool operator() (const Brick lhs, const Brick rhs) {
return (lhs.getTrackCostUpToMe() > rhs.getTrackCostUpToMe());
}
};
public:
Manager();
~Manager();
void Start();
void parseText();
void presentBoard() const;
const void checkNeighbours( int i, int j,const int x,const int y,stack<Brick> *tempStack, const Brick father)const;
void returnNeighbours(const Brick node, stack<Brick>* tempStack,const Brick father);
bool DFS(const Brick node,const int depth,const Brick father)const;
void parseSolution();
void IDDFS();
void printSolution()const;
bool UCS();
};
and here's the UCS function:
bool Manager::UCS()
{
priority_queue<Brick,vector<Brick>,ComparatorGreaterThan> myQueue;
myQueue.push(myBoard->getRoot());
mySet.insert(myBoard->getRoot().getCoorddinates());//Set is used to know which elements,using the coordiantes, are in the PQ
while (!myQueue.empty())
{
Brick parent = myQueue.top();
myQueue.pop();
mySet.erase(parent.getCoorddinates());
if (parent.getSym() == 'G')//If goal is found
{
cout << parent.getTrackCostUpToMe();
return true;
}
stack<Brick> tempStack;//Keeps all the neighbours of current node.
returnNeighbours(parent, &tempStack,myBoard->getNode(parent.getFatherX(),parent.getFatherY()));//Finds all the neighbours of current node.
while (!tempStack.empty())
{
tempStack.top().setTrackCostUpToMe(parent.getTrackCostUpToMe());//Set the track cost of neighbour.
if (mySet.find(tempStack.top().getCoorddinates()) == mySet.end())//If we don't have neighrbour in the PQ
{
mySet.insert(tempStack.top().getCoorddinates());
myQueue.push(tempStack.top());
tempStack.pop();
}
else //We have the neighbour in the PQ
tempStack.pop();
}
}
return false;
}
Related
I am trying to construct a child class object from a base class object. I have tried the below code.
class A
{
public:
A();
A(A&& objectName) = default;
virtual void setint(int i);
virtual void getint();
int var;
};
class B: public A
{
public:
virtual void getint();
B(A&& objectName);
int j= 20;
};
A::A()
{
}
void A::setint(int i)
{
var = i;
}
void A::getint()
{
qDebug()<<"From A Var"<<var;
}
void B::getint()
{
qDebug()<<"From B j"<<j;
qDebug()<<"From B Var"<<var;
}
B::B(A&& objectName): A(std::move(objectName))
{
}
And in my Main.cpp I am doing this
#include <memory>
int main(int argc, char *argv[])
{
A *obj = new A();
obj->setint(10);
obj->getint();
A *obj1 = new B(std::move(*obj));
obj->getint();
obj1->getint();
return 0;
}
The result I get is
From A Var 10
From A Var 10
From B j 20
From B Var 10
My question is why am I getting the value of Var after A *obj1 = new B(std::move(*obj)); this line. I thought the object pointed by obj must have been destructed.
Let me copy paste from this answer: https://stackoverflow.com/a/15663912/512225
std::move doesn't move from the object. It just returns an rvalue reference whose referand is the object, making it possible to move from the object.
Anyway your code is terrible. I hope you know. If you don't, ask for a review.
I try to fill a struct object with a variable Char Array, but it doesn't work.
The result are random symbols.
If I enter the "naamBestand"manually in the MyObject Temp, the correct answer will come out. What am I doing wrong?
struct MyObject {
char bestandsnaam[12];
int beginpositie;
int lengte;
};
void setup() {
Serial.begin(9600);
updateEEPROM(0, "test", 1, 1);
}
void loop() {
}
void updateEEPROM(int locatie, char naamBestand[12], int positieBestand, int lengteBestand) {
MyObject temp {naamBestand, positieBestand , lengteBestand};
Serial.println(temp.bestandsnaam);
//EEPROM.put(locatie, temp);
}
The solution!
typedef struct MyObject {
char bestandsnaam[12];
int beginpositie;
int lengte;
};MyObject customVar;
void setup() {
Serial.begin(9600);
updateEEPROM(0, "test", 1 , 2);
}
void loop() {
}
void updateEEPROM(int locatie, char naamBestand[12], int positieBestand, int lengteBestand) {
strcpy(customVar.bestandsnaam, naamBestand);
customVar.beginpositie = positieBestand;
customVar.lengte = lengteBestand;
Serial.println(customVar.bestandsnaam);
//EEPROM.put(locatie, customVar);
i'm trying to create a room which has a goldContainer
The goldContainer is defined in a separate .h file.
When i'm trying to compile it says
error C2079: 'room::goldC' uses undefined class 'goldContainer'
The class voor room:
#pragma once
#include <SFML\Graphics.hpp>
#include "screenSettings.h"
#include "floorplanPatch.h"
#include "floorplanPatchContainer.h"
#include "enemyContainer.h"
#include "goldContainer.h"
class goldContainer;
class room{
public:
room(int themenr, floorplanPatchContainer &f);
void draw(sf::RenderWindow &window);
int getStartPoint();
int getEndPoint();
void addFloorplanPatch(int x, int y, int type, floorplanPatch *patch);
bool isSolid(sf::Vector2f position);
void addEnemy();
static const int FLOOR_TEXTURE1 = 0;
static const int FLOOR_TEXTURE2 = 1;
static const int FLOOR_TEXTURE3 = 2;
static const int FLOOR_TEXTURE4 = 3;
static const int WALL = 4;
static const int OBSTACLE = 5;
static const int COSMETIC = 6;
int floorplan[xAs][yAs];
enemyContainer* getEnemyContainer();
void room::addEnemy(int health);
private:
enemyContainer ec;
int startPoint = 1 + rand() % (yAs - 2);
int endPoint = 1 + rand() % (yAs - 2);
sf::RectangleShape rectangle{ sf::Vector2f{ tileSizeX, tileSizeY } };
sf::Texture wall;
sf::Texture obstacle;
sf::Texture floor1;
sf::Texture floor2;
sf::Texture floor3;
sf::Texture floor4;
sf::Texture cosmetic;
void drawBackgroundTile(sf::RenderWindow &window, int i, int x, int y);
goldContainer goldC;
};
it has class goldContainer; on line 8 otherwise it generates error code 2146.
Could someone maybe explain how to solve this error and/or why this occurs.
#pragma once
#include "gold.h"
#include "sound.h"
#include "player.h"
class player;
class room;
class goldContainer{
public:
goldContainer();
~goldContainer();
void checkPickedUp(player &player);
void draw(sf::RenderWindow &window);
void addGold(int amount, sf::Vector2f position, sf::Vector2f size);
void clearAllGold();
private:
std::vector<gold* > goldDrops;
sound goldPickup{ "sounds\\goldPickup.wav" };
};
I think it might be a circular depedency trough:
^->goldContainer->player->roomContainer->room->|
|<-<-<-<-<-<-<-<-<-<-<-<-<-<-<-<-<-<-<-<-<-<-< v
Let me show you the problem domain:
class Moon;
class Sun
{
void Rotate(Moon);
};
Now, you implement Sun::Rotate, without giving any class declaration (not forward declaration):
void Sun::Rotate(Moon m) // Error C2027
{
}
What you can do:
Ensure that before Sun::Rotate gets into compilation phase, Moon is declared (i.e. known to compiler by now). You need not to implement any method of Moon, just declare.
Example:
class Moon;
class Sun
{
void Rotate(Moon);
};
// Let it come by now
class Moon
{
public:
void PleaseRotate();
};
// Moon is known
void Sun::Rotate(Moon m)
{
m.PleaseRotate(); // It need not to be implemented by now.
}
Note that Moon::PleaseRotate definition would be resolved by linker, and hence its implementation is not needed before Sun::Rotate.
I've been trying to get a project rid of every boost reference and switch to pure C++11.
At one point, thread workers are created which wait for a barrier to give the 'go' command, do the work (spread through the N threads) and synchronize when all of them finish. The basic idea is that the main loop gives the go order (boost::barrier .wait()) and waits for the result with the same function.
I had implemented in a different project a custom made Barrier based on the Boost version and everything worked perfectly. Implementation is as follows:
Barrier.h:
class Barrier {
public:
Barrier(unsigned int n);
void Wait(void);
private:
std::mutex counterMutex;
std::mutex waitMutex;
unsigned int expectedN;
unsigned int currentN;
};
Barrier.cpp
Barrier::Barrier(unsigned int n) {
expectedN = n;
currentN = expectedN;
}
void Barrier::Wait(void) {
counterMutex.lock();
// If we're the first thread, we want an extra lock at our disposal
if (currentN == expectedN) {
waitMutex.lock();
}
// Decrease thread counter
--currentN;
if (currentN == 0) {
currentN = expectedN;
waitMutex.unlock();
currentN = expectedN;
counterMutex.unlock();
} else {
counterMutex.unlock();
waitMutex.lock();
waitMutex.unlock();
}
}
This code has been used on iOS and Android's NDK without any problems, but when trying it on a Visual Studio 2013 project it seems only a thread which locked a mutex can unlock it (assertion: unlock of unowned mutex).
Is there any non-spinning (blocking, such as this one) version of barrier that I can use that works for C++11? I've only been able to find barriers which used busy-waiting which is something I would like to prevent (unless there is really no reason for it).
class Barrier {
public:
explicit Barrier(std::size_t iCount) :
mThreshold(iCount),
mCount(iCount),
mGeneration(0) {
}
void Wait() {
std::unique_lock<std::mutex> lLock{mMutex};
auto lGen = mGeneration;
if (!--mCount) {
mGeneration++;
mCount = mThreshold;
mCond.notify_all();
} else {
mCond.wait(lLock, [this, lGen] { return lGen != mGeneration; });
}
}
private:
std::mutex mMutex;
std::condition_variable mCond;
std::size_t mThreshold;
std::size_t mCount;
std::size_t mGeneration;
};
Use a std::condition_variable instead of a std::mutex to block all threads until the last one reaches the barrier.
class Barrier
{
private:
std::mutex _mutex;
std::condition_variable _cv;
std::size_t _count;
public:
explicit Barrier(std::size_t count) : _count(count) { }
void Wait()
{
std::unique_lock<std::mutex> lock(_mutex);
if (--_count == 0) {
_cv.notify_all();
} else {
_cv.wait(lock, [this] { return _count == 0; });
}
}
};
Here's my version of the accepted answer above with Auto reset behavior for repetitive use; this was achieved by counting up and down alternately.
/**
* #brief Represents a CPU thread barrier
* #note The barrier automatically resets after all threads are synced
*/
class Barrier
{
private:
std::mutex m_mutex;
std::condition_variable m_cv;
size_t m_count;
const size_t m_initial;
enum State : unsigned char {
Up, Down
};
State m_state;
public:
explicit Barrier(std::size_t count) : m_count{ count }, m_initial{ count }, m_state{ State::Down } { }
/// Blocks until all N threads reach here
void Sync()
{
std::unique_lock<std::mutex> lock{ m_mutex };
if (m_state == State::Down)
{
// Counting down the number of syncing threads
if (--m_count == 0) {
m_state = State::Up;
m_cv.notify_all();
}
else {
m_cv.wait(lock, [this] { return m_state == State::Up; });
}
}
else // (m_state == State::Up)
{
// Counting back up for Auto reset
if (++m_count == m_initial) {
m_state = State::Down;
m_cv.notify_all();
}
else {
m_cv.wait(lock, [this] { return m_state == State::Down; });
}
}
}
};
Seem all above answers don't work in the case the barrier is placed too near
Example: Each thread run the while loop look like this:
while (true)
{
threadBarrier->Synch();
// do heavy computation
threadBarrier->Synch();
// small external calculations like timing, loop count, etc, ...
}
And here is the solution using STL:
class ThreadBarrier
{
public:
int m_threadCount = 0;
int m_currentThreadCount = 0;
std::mutex m_mutex;
std::condition_variable m_cv;
public:
inline ThreadBarrier(int threadCount)
{
m_threadCount = threadCount;
};
public:
inline void Synch()
{
bool wait = false;
m_mutex.lock();
m_currentThreadCount = (m_currentThreadCount + 1) % m_threadCount;
wait = (m_currentThreadCount != 0);
m_mutex.unlock();
if (wait)
{
std::unique_lock<std::mutex> lk(m_mutex);
m_cv.wait(lk);
}
else
{
m_cv.notify_all();
}
};
};
And the solution for Windows:
class ThreadBarrier
{
public:
SYNCHRONIZATION_BARRIER m_barrier;
public:
inline ThreadBarrier(int threadCount)
{
InitializeSynchronizationBarrier(
&m_barrier,
threadCount,
8000);
};
public:
inline void Synch()
{
EnterSynchronizationBarrier(
&m_barrier,
0);
};
};
I'm trying to transfer a command line code that I have to a more visual program with a
GUI to enable easier use. The original code was in C++, so I'm using Visual C++ that is
available in Visual Studio Express 2012, but I have problems understanding the "new"
managed C++/CLI way of handling objects. Being new to CLI and managed C++, I was wondering
if someone can explain what I am doing wrong, and why it doesn't work. Now here is a
description of the code and the problem.
The program is essentially an optimization program:
There are multiple boxes (modes) in a system, each mode, depending on its type has a
few numerical coefficients that control its behavior and the way it responds to outside
excitation.
The program asks the user to specify the number of boxes and the type of each box.
Then tries to find the numerical coefficients that minimize the difference between
the system response with those obtained experimentally.
So, the UI has means for user to open the experimental result files, specify the number
of modes, and specify the type of each mode. Then, the user can initiate the processing
function by clicking on a start button, that initiates a background worker.
Following the example given in MSDN, I created a class that performs the work:
ref class curveFit
{
public: ref class CurrentState{
public:
int percentage;
int iterationNo;
int stage;
bool done;
multimode systemModel;
};
public:
int modes;
int returncode;
array<double> ^expExcitations;
array<double> ^expResults;
multimode systemModel;
private:
void fcn(int, int, double*, double*, int*);
double totalError(std::vector<double> &);
public:
delegate void fcndelegate(int, int, double*, double*, int*);
public:
curveFit(void);
curveFit^ fit(System::ComponentModel::BackgroundWorker^, System::ComponentModel::DoWorkEventArgs^, Options^);
};
multimode is just a container class: a list of different boxes.
ref class multimode
{
private:
Collections::Generic::List<genericBoxModel ^>^ models;
int modes;
public:
multimode(void);
multimode(const multimode%);
int modeNo(void);
void Add(genericBoxModel^);
void Clear();
genericBoxModel^ operator[](int);
multimode% operator=(const multimode%);
double result(double);
bool isValid();
std::vector<double> MapData();
void MapData(std::vector<double> &);
};
multimode::multimode(void)
{
models = gcnew Collections::Generic::List<genericBoxModel ^>();
modes = 0;
}
multimode::multimode(const multimode% rhs)
{
models = gcnew Collections::Generic::List<genericBoxModel ^>();
for(int ind = 0; ind < rhs.modes; ind++)
models->Add(rhs.models[ind]);
modes = rhs.modes;
}
int multimode::modeNo(void)
{
return modes;
}
void multimode::Add(genericBoxModel^ model)
{
models->Add(model);
modes++;
}
void multimode::Clear()
{
models->Clear();
modes = 0;
}
genericBoxModel^ multimode::operator[](int ind)
{
return models[ind];
}
multimode% multimode::operator=(const multimode% rhs)
{
models->Clear();
for(int ind = 0; ind < rhs.modes; ind++)
models->Add(rhs.models[ind]);
modes = rhs.modes;
return *this;
}
double multimode::result(double excitation)
{
double temp = 0.0;
for(int ind = 0; ind < modes; ind++)
temp += models[ind]->result(excitation);
return temp;
}
bool multimode::isValid()
{
bool isvalid = true;
if(modes < 1)
return false;
for(int ind = 0; ind < modes; ind++)
isvalid = (isvalid && models[ind]->isValid());
return isvalid;
}
std::vector<double> multimode::fullMap()
{
//Map the model coefficients to a vector of doubles
...
}
void multimode::fullMap(std::vector<double> &data)
{
//Map a vector of doubles to the model coefficients
...
}
and genericBoxModel is an abstract class that all box models are based on.
The curvefit::fit function does the optimization based on the options passed to it:
curveFit^ curveFit::fit(System::ComponentModel::BackgroundWorker^ worker, System::ComponentModel::DoWorkEventArgs^ e, Options^ opts)
{
fcndelegate^ del = gcnew fcndelegate(this, &curveFit::fcn);
std::vector<double> data;
CurrentState^ state = gcnew CurrentState;
state->done = false;
state->stage = 0;
state->percentage = 0;
state->systemModel = systemModel;
worker->ReportProgress(state->percentage, state);
switch(opts->optimizationMethod)
{
case 0:
while(iterationNo < maxIterations)
{
data = systemModel.MapData();
OptimizationMethod0::step(some_parameters, data, (optmethods::costfunction)Runtime::InteropServices::Marshal::GetFunctionPointerForDelegate(del).ToPointer());
systemModel.MapData(data);
iterationNo++;
state->percentage = 0;
state->systemModel = systemModel;
worker->ReportProgress(state->percentage, state);
}
...
}
}
I'm passing the system model inside the state so that I can display the results of the
latest step on the screen, which doesn't work, but that is another question :-)
The start button calls the curvefit::fit function after initializing the system model:
private: System::Void btnStart_Click(System::Object^ sender, System::EventArgs^ e) {
systemModel.Clear();
for(int mode = 0; mode < modes; mode++)
{
switch(model)
{
case 0:
systemModel.Add(gcnew model0);
systemModel[mode]->coefficients[0] = 100.0 / double(mode + 1);
...
break;
...
}
}
btnStart->Enabled = false;
stStatusText->Text = "Calculating!";
Application::UseWaitCursor = true;
curveFit^ cf = gcnew curveFit;
fitCurve->RunWorkerAsync(cf);
}
private: System::Void fitCurve_DoWork(System::Object^ sender, System::ComponentModel::DoWorkEventArgs^ e) {
System::ComponentModel::BackgroundWorker^ worker;
worker = dynamic_cast<System::ComponentModel::BackgroundWorker^>(sender);
curveFit^ cf = safe_cast<curveFit^>(e->Argument);
cf->expExcitations = gcnew array<double>(expExcitations.Count);
expExcitations.CopyTo(cf->expExcitations);
cf->expResults = gcnew array<double>(expResults.Count);
expResults.CopyTo(cf->expResults);
cf->systemModel = systemModel;
cf->modes = modes;
e->Result = cf->fit(worker, e, options);
}
This works perfectly! But, in order to make the optimization process faster and more
successful, I wanted to use the results of previous optimizations as the initial guess
for the next run (if possible):
multimode oldmodel(systemModel);
systemModel.Clear();
for(int mode = 0; mode < modes; mode++)
{
switch(model)
{
case 0:
if(mode < oldmodel.modeNo() && oldmodel.isValid() && (oldmodel[mode]->model == 0))
systemModel.Add(oldmodel[mode]);
else
{
systemModel.Add(gcnew model0);
systemModel[mode]->coefficients[0] = 100.0 / double(mode + 1);
...
}
break;
...
Now, my problem is, after this change, it seems that the messages don't get passed
correctly: the first time the start button is clicked everything functions as it should,
but from then on, if the statement systemModel.Add(oldmodel[mode]); gets executed,
results remain the same as the initial guesses, and don't get updated after the fit
function is called.
So, why should these two lines(Add(oldmodel[mode]) and Add(gcnew model0)) give
such different results?