I made a program for binary heap given below-
#include<iostream>
using namespace std;
/**
* Construct the binary heap.
* capacity is the capacity of the binary heap.
*/
class BinaryHeap
{
private:
int currentSize; // Number of elements in heap
int array[]; // The heap array
void buildHeap( );
void percolateDown( int hole );
public:
bool isEmpty( ) const;
bool isFull( ) const;
int findmini( ) const;
void insert( int x );
void deleteMin( );
void deleteMin( int minItem );
void makeEmpty( );
public :
BinaryHeap( )
{
currentSize = 0;
}
BinaryHeap( int capacity )
{
array[capacity + 1];
currentSize = 0;
}
};
int main()
{
int resp, ch, choice;
int n, i;
cout << "enter the size of heap" << endl;
cin >> n;
BinaryHeap b(int n);
cout << "enter the item " << endl;
cin >> ch;
b.insert( int ch);
return 0;
}
while compiling it gives errors
request for member 'insert' in 'b', which is of non-class type 'BinaryHeap(int)'
and
expected primary-expression before 'int'
why is this happening and how could it be resolved?
Remove int from BinaryHeap b(int n); and b.insert( int ch); and you are good to go.
When you call a function you shouldn't specify the data type of the variables you call it with.
Try changing this
b.insert( int ch);
to this:
b.insert(ch);
Related
I have a problem with my code. Unfortunately, when compiling I get these errors all the time. What can this be caused by and how to fix it?
error C3861: 'print': identifier not found
My code:
main.cpp
#include "pojazdy.h"
#include <iostream>
using namespace std;
int main()
{
Pojazdy** poj;
int size{ 0 }, index{ 0 };
Petla(poj, size);
print(poj, size);
wyrejestruj(poj,size,0);
print(poj, size);
wyrejestruj(poj,size);
return 0;
}
pojazdy.h
#ifndef pojazdy_h
#define pojazdy_h
#include <iostream>
#include <cstdlib>
using namespace std;
class Pojazdy
{
public:
string typ;
string marka;
string model;
string z_dod;
int ilosc;
int cena;
void dodaj();
void d_pojazd(Pojazdy**& pojazdy, int& size);
void wyrejestruj(Pojazdy**& pojazdy, int& size, int index);
void print(Pojazdy** pojazdy, int size);
void Petla(Pojazdy**& p, int& size);
//void wyswietl();
int get_ilosc() { return ilosc; }
string get_typ() { return typ; }
string get_marka() { return marka; }
string get_model() { return model; }
int get_cena() { return cena; }
void set_ilosc(int x);
};
#endif
pojazdy.cpp
#include "pojazdy.h"
#include <iostream>
using namespace std;
void Pojazdy::set_ilosc(int x) { ilosc = x; }
void Pojazdy::dodaj()
{
cout << "DODAWANIE POJAZDU..." << endl;
cout << "Podaj typ pojazdu:";
cin >> typ;
cout << "Podaj marke pojazdu: ";
cin >> marka;
cout << "Podaj model pojazdu: ";
cin >> model;
cout << "Dodaj cene pojazdu: ";
cin >> cena;
}
void Petla(Pojazdy**& p, int& size) {
char z_dod;// = 'N';
do {
d_pojazd(p, size); //odpowiada za dodawnie
p[size - 1]->dodaj();
cout << "Czy chcesz zakonczyc dodawanie? Jesli tak, wcisnij Y/N: ";
cin >> z_dod;
} while (z_dod == 'N' || z_dod == 'n');//while (p[size]->z_dod == "N" ||p[size]->z_dod == "n");
}
void print(Pojazdy** pojazdy, int size) {
std::cout << "====================================" << std::endl;
for (int i{ 0 }; i < size; i++)
std::cout << "Typ: " << pojazdy[i]->get_typ() << " Marka: " << pojazdy[i]->get_marka() << " Model: " << pojazdy[i]->get_model() << " Cena: " << pojazdy[i]->get_model() << std::endl;
}
void wyrejestruj(Pojazdy**& pojazdy, int& size) {
for (size_t i{ 0 }; i < size; i++)
delete pojazdy[i];
delete[] pojazdy;
size = 0;
pojazdy = NULL;
}
void wyrejestruj(Pojazdy**& pojazdy, int& size, int index) {
if (index < size) {
Pojazdy** temp = new Pojazdy * [size - 1];
short int j{ -1 };
for (size_t i{ 0 }; i < size; i++) {
if (i != index) {
j++;
temp[j] = pojazdy[i];
}
}
delete[] pojazdy;
--size;
pojazdy = temp;
}
else
std::cout << "Pamiec zwolniona!" << std::endl;
}
void d_pojazd(Pojazdy**& pojazdy, int& size) {
Pojazdy** temp = new Pojazdy * [size + 1];
if (size == 0)
temp[size] = new Pojazdy;
else {
for (int i{ 0 }; i < size; i++)
temp[i] = pojazdy[i];
delete[] pojazdy;
temp[size] = new Pojazdy;
}
++size;
pojazdy = temp;
}
I used #ifndef, #define, #endif and #pragma once, but none of them work. I will be really grateful for every code, I am already tired of this second hour. And forgive the non-English variables and function names for them - it's university code, so I didn't feel the need.
Move the functions below outside the class declaration.
void wyrejestruj(Pojazdy**& pojazdy, int& size, int index);
void print(Pojazdy** pojazdy, int size);
void Petla(Pojazdy**& p, int& size);
Or make them static and call like Pojazdy::print(poj, size);.
You declared a non-static member function print in the class definition
class Pojazdy
{
public:
// ...
void print(Pojazdy** pojazdy, int size);
//...
but you are trying to call it as a stand-alone function in main
print(poj, size);
So the compiler issues an error.
The declaration of the function as a stand alone function that at the same time is its definition in the file pojazdy.cpp is not visible in the module with main because this module includes only the header with the class declaration.
You should decide whether this function should be a member function of the class or a stand alone function.
You are not calling your member functions correctly. print can only be called on an object of type Pojazdy, so you need to do something like:
Pojazdy** poj;
int size{ 0 }, index{ 0 };
Pojazdy x; // Creates an object of Pojazdy called z
x.print(poj,size); // Calls the print method on x
Alternatively, if you don't want to have to declare an object, you could make the method static and just call it on the class.
In the .h file:
static void print(Pojazdy** pojazdy, int size);
And then in main:
Pojazdy** poj;
int size{ 0 }, index{ 0 };
Pojazdy::print(poj, size); // Calls the print method on the class
You put your function prototypes in the wrong place. They should be after the class decalration.
class Pojazdy
{
...
};
void print(Pojazdy** pojazdy, int size);
void wyrejestruj(Pojazdy**& pojazdy, int& size);
etc.
print is not a member of the Pojazdy class, so it's wrong to put the prototype inside the Pojazdy class declaration.
I need help... appropriate questions have been asked in the comments. The programs has zero compiler errors and warnings!! I have concerns with calling a member function from another member function using function pointers. (To be precise, setMatrixto() is trying to call setElement() function using function pointer)
Plus somehow the "hello there" is not being printed to the console. I was expecting it to show up as output.Maybe the setMatrixto() is not getting called at all!!
Header File definition
#ifndef MATRIXOPERATIONS_H
#define MATRIXOPERATIONS_H
class MatrixOperations;
typedef int (MatrixOperations::*INTFUNC)(int,int);
typedef void (MatrixOperations::*VOIDFUNC)(int,int,int);
class MatrixOperations
{
public:
MatrixOperations();
MatrixOperations(int size);
~MatrixOperations();
//diagonal matrix funtions
void displayMatrixOf(INTFUNC f);
void setMatrixTo(VOIDFUNC f);
int getElement(INTFUNC from, int i, int j);
void setElement(VOIDFUNC to,int i ,int j, int value);
int fromDiagonalArray(int i, int j);
void toDiagonalArray(int i, int j, int value);
protected:
private:
int size;
int* a;
};
#endif // MATRIXOPERATIONS_H
CPP Implementation File
#include "MatrixOperations.h"
#include <iostream>
using namespace std;
MatrixOperations::MatrixOperations()
{
//ctor
size = 3;
a = new int[size];
}
MatrixOperations::MatrixOperations(int size)
{
//ctor
this->size = size;
a = new int[size];
}
MatrixOperations::~MatrixOperations()
{
//dtor
delete[] a;
}
///////////////////FUCNTION POINTER SECTION///////////////////////////////////
int MatrixOperations::getElement(INTFUNC from, int i, int j)
{
return (this->*from)(i,j);
}
void MatrixOperations::setElement(VOIDFUNC to,int i ,int j, int value)
{
(this->*to)(i,j,value);
}
/////////////////////////////////DIAGONAL ARRAY OPERATIONS/////////////////////////////////////////////////
int MatrixOperations::fromDiagonalArray(int i, int j)
{
if(i==j)
{
return a[i];
}
else
{
return 0;
}
}
void MatrixOperations::toDiagonalArray(int i, int j, int value)
{
a[i] = value;
}
///////////////////////////////////////////////////////////////////
void MatrixOperations::displayMatrixOf(INTFUNC f)
{
for(int i{0}; i < size; i++)
{
for(int j{0}; j < size; j++)
{
cout << getElement(f,i,j) << "\t"; //is this the correct way to send the function pointer?
}
cout << endl;
}
}
void MatrixOperations::setMatrixTo(VOIDFUNC f)
{
cout << "Hello there!!"; //not getting this output.. whats wrong??
for(int i{0}; i < size; i++)
{
int value {};
cout << "Enter value diagonal element " << i << " : ";
cin >> value;
setElement(f,i,i,value); //is this the correct way to send the function pointer?
}
}
///////////////////////////////////////////////////////////////////////////////
Main File
#include <iostream>
#include "MatrixOperations.h"
typedef MatrixOperations MATRIX;
using namespace std;
int main()
{
MATRIX m1;
m1.setMatrixTo(MATRIX::toDiagonalArray); //was expecting a "Hello there!" but i am not getting that output either
return 0;
}
EDIT2: I added all the class definitions and main function in one single file. SURPRISINGLY!! this works . I am confused??!!!
#include <iostream>
using namespace std;
class MatrixOperations;
typedef void (MatrixOperations::*VOIDFUNC)(int,int,int);
typedef MatrixOperations MATRIX;
class MatrixOperations
{
public:
MatrixOperations();
MatrixOperations(int size);
~MatrixOperations();
//diagonal matrix funtions
void setMatrixTo(VOIDFUNC f);
void setElement(VOIDFUNC to,int i ,int j, int value);
void toDiagonalArray(int i, int j, int value);
private:
int size;
int* a;
};
MatrixOperations::MatrixOperations()
{ //ctor
size = 3;
a = new int[size];
}
MatrixOperations::MatrixOperations(int size)
{ //ctor
this->size = size;
a = new int[size];
}
MatrixOperations::~MatrixOperations()
{
//dtor
delete[] a;
}
void MatrixOperations::setElement(VOIDFUNC to,int i ,int j, int value)
{
(this->*to)(i,j,value);
}
/////////////////////////////////DIAGONAL ARRAY OPERATIONS/////////////////////////////////////////////////
void MatrixOperations::toDiagonalArray(int i, int j, int value)
{
a[i] = value;
}
///////////////////////////////////////////////////////////////////
void MatrixOperations::setMatrixTo(VOIDFUNC f)
{
cout << "Hello there!!" << endl;
for(int i{0}; i < size; i++)
{
int value {};
cout << "Enter value diagonal element " << i << " : ";
cin >> value;
setElement(f,i,i,value);
}
}
int main()
{
MATRIX m1;
m1.setMatrixTo(MATRIX::toDiagonalArray);
return 0;
}
There is nothing wrong with the code in both cases. Its just my debugger was not running in admin mode. I got error code 740. So I launched my IDE in admin mode and voila it worked.
Why can't use nullptr in the constructor function?( the function name: Wine) When i try to do this, the program will break down and no any error report maybe because i don't the reason for that.
#ifndef WINE_H_
#define WINE_H_
#include<iostream>
#include<string>
#include<valarray>
using std::string;
using std::valarray;
template<typename T1, typename T2>
class Pair //member of the wine
{
private:
T1 a;
T2 b;
public:
T1 & first(){ return a; }
T2 & second(){ return b; }
T1 first()const{ return a; }
T2 second()const{ return b; }
Pair(const T1 & aval, const T2 & bval) :a(aval), b(bval){}
Pair(){}
};
typedef valarray<int>ArrayInt;
typedef Pair<ArrayInt, ArrayInt>PairArray;
class Wine
{
private:
string name;
PairArray bt;
int years;
public:
Wine();
Wine(const char * a, int y,int b[], int c[]); //no problem
Wine(const char * a, int y); //here is that problem function
void GetBottles(); //no problem
void Show()const; //no problem
int Sum(){ return bt.second().sum(); }
};
Wine::Wine(const char * a, int y) :name(a), years(y), bt(ArrayInt(0, y), ArrayInt(0, y)){}
**//When I am trying to use nullptr to instead 0 in the ArrayInt(0,y),the whole program will break down during work.**
Wine::Wine(const char * a, int y, int b[], int c[]) :bt(ArrayInt(b, y), ArrayInt(c, y))
{
name = a;
years = y;
}
Wine::Wine() :bt(ArrayInt(),ArrayInt())
{
name = "null";
years = 0;
}
void Wine::GetBottles()
{
std::cout << "Please input the years and the bottles\n";
for (int i = 0; i < years; i++)
{
std::cout << "input the year: ";
(std::cin >> bt.first()[i]).get();
std::cout << "input the bottles";
(std::cin >> bt.second()[i]).get();
}
}
void Wine::Show()const
{
using std::cout;
using std::endl;
for (int i = 0; i < years; i++)
{
cout << bt.first()[i] << '\0' << bt.second()[i] << endl;
}
}
#endif
#include<iostream> //test part
#include"wine.h"
int main(void)
{
using std::cin;
using std::cout;
using std::endl;
cout << "Enter name of wine: ";
char lab[50];
cin.getline(lab, 50);
cout << "Enter number of years: ";
int yrs;
cin >> yrs;
Wine holding(lab, yrs);
holding.GetBottles();
holding.Show();
return 0;
}
Thank your for your help!
This is a funny one. The reason why it breaks in one example, but not another is following:
There are two different constructors for std::valarray (more than that, but those two matter):
valarray( const T& val, std::size_t count ); // 1
valarray( const T* vals, std::size_t count ); // 2
When you use 0 (valarray(0, y)) you are calling the first version - creating an array of y elements, where every element is initialized to 0.
But when you are calling it with nullptr, you are calling the second version of it - trying to initialize your new array with a copy from an array pointed to by the first argument to the constructor. But your first argument is nullptr, and any attempt to use at as an array triggers undefined behavior, and program crashes.
this is my code:
class Node {
private:
unsigned number;
unsigned color;
public:
Knoten(unsigned int number = 0, unsigned int color = 0)
{}
void set_number(unsigned int a){
number = a;
}
void set_color(unsigned int b){
color = b;
}
unsigned int get_number(void){
return number;
}
unsigned int get_color(void){
return color;
}
void print(void){
cout << number << " " << color << endl;
}
};
int main(){
Node node1, node 2, node 3;
Knoten* n1,n2,n3;
n1=&node1;
n2=&node1;
n3=&node1;
node1.set_number(1);
node1.set_color(3);
node2.set_number(2);
node2.set_color(5);
node3.set_number(3);
node3.set_color(7);
node1.ausgabe();
node2.ausgabe();
node3.ausgabe();
Node* matrix[2][2];
return 0;
Ok, i want to save the pointer in the array.
Once they are in the array, how do I edit the properties of each Array elements.
For Example.
n1 is save in matrix[0][0].
and the color is change from 3 to 10.
How i do this.
Thanks
If I have correctly understood you and if do not take into account your invalid code then you can use expression
matrix[0][0]->set_color( 10 );
Or
if ( matrix[0][0]->get_color() == 3 ) matrix[0][0]->set_color( 10 );
I am trying to create a vector of objects but i have some issues. I can't push_back over 19 objects to my vector because it shows up an error message of bad_alloc.
I try to resize my vector with resize() or reserve() but still nothing.
For resize(), I read that you need to provide 2 arguments to resize a vector.But still nothing.
When I try to use it without push_back it shows error: expected primary-expression before ')' token.
#define N 10 //ari8mos seirwn tou xarth
#define M 10 //ari8mos sthlwn tou xarth
#define TREAS 100//posothta 8usaurou
#define PORTS 100//ari8mos limaniwn
extern void ships(map (&myArray)[N][M], vector<ship> &myShips);
void ships(map (&myArray)[N][M], vector<ship> &myShips)
{
int i,j,y;
srand ( time(NULL) );
//myShips.reserve(21);
//myShips.resize(20,ship);
cout << myShips.capacity() << endl;
int x=0;
for( i = 0; i <19 ; i++){
myShips.push_back(pirate(rand() % N,rand() % M,100,100,100,1,'#',myArray,myShips));
}
for( i=0;i<myShips.size();i++ ){
cout << myShips[i].get_symbol() << " ";
}
}
here is the rest of code to help you understand:
class ship
{
protected:
int i,j,x2,y2;
//vector<vector<map> > myArray;
//ship (&myShips)[N][M];
int x;
int y;
map (myArray)[N][M];
vector<ship> myShips;
int max_resistance;
int current_resistance;
int speed;
int reserve_treasure;
char symbol;
public:
ship(int x_, int y_, int max_res, int cur_res, int res_treas, int sp, char sy, map (&myArr)[N] [M], vector<ship> &Ship)
:x(x_)
,y(y_)
,max_resistance(max_res)
,current_resistance(cur_res)
,reserve_treasure(res_treas)
,speed(sp)
,symbol(sy)
,myArray(myArr)
,myShips(Ship)
{cout << "eimai o 'ship' 2" << endl; }
~ship() {}
int get_x();
int get_y();
float get_max_resistance();
float get_current_resistance();
int get_speed();
float get_reserve_treasure();
char get_symbol();
void set_x(int pos_x);
void set_y(int pos_y);
void set_max_resistance(float maxres);
void set_current_resistance(float curres);
void set_speed(int sp);
void set_reserve_treasure(float restrea);
void set_symbol(char sy);
void movement();
void operation();
};
int ship::get_x(){
return x;
}
int ship::get_y(){
return y;
}
float ship::get_max_resistance(){
return max_resistance;
}
float ship::get_current_resistance(){
return current_resistance;
}
int ship::get_speed(){
return speed;
}
float ship::get_reserve_treasure(){
return reserve_treasure;
}
char ship::get_symbol(){
return symbol;
}
void ship::set_x(int pos_x){
x = pos_x;
}
void ship::set_y(int pos_y){
y = pos_y;
}
void ship::set_max_resistance(float maxres){
max_resistance = maxres;
}
void ship::set_speed(int sp){
speed = sp;
}
void ship::set_current_resistance(float curres){
current_resistance = curres;
}
void ship::set_reserve_treasure(float restrea){
reserve_treasure = restrea;
}
void ship::set_symbol(char sy){
symbol = sy;
}
class pirate : public ship
{
public:
pirate(int posx, int posy, float mr, float cr, float rt, int spe, char sym, map (&Array)[N] [M],vector<ship> &Ship ):ship(posx,posy,mr,cr,rt,spe,sym,Array,Ship){
cout << "eimai o 'pirate' 1" << endl;
// ship(90,90,1,50,'#',Array,Ship) {//vector<vector<map> > Array, vector<vector<ship> > Ship) {}
};
Hope you can help
Looking through this code, did you create a custom definition for map? Otherwise, if you are trying to create an [N][M] array of Map objects, you are missing the type declaration of map. e.g. map<int,string>
If you are trying to use map as a multidimensional array, this is not what std::map is for. Map is a generic container for storing key/value pairs.