I am an IT student currently learning linked list. I have a problem with my code here. After I call addFront() my list doesn't change when I display it. How do I somewhat change/fill my list without changing the function type? I know it works on pointers still messed up with linked list.
Code:
typedef struct node *nodeptr;
struct node{int item;
nodeptr next;};
typedef nodeptr List;
}
[code]....
I'm having some problems with changing an array of numbers of type char to type int. Every time i try to sum 2 array indexed values it returns some letter or symbol. Also, if i change the type of the array in the functions the compiler gives me an error message. I would also like to add that the problem requires that the first two arrays be char so each individual number gets assigned to a different value.
My current code is:
Code:
#include <iostream>
void input(char a[], char b[], int& size_a, int& size_b);
void convert(char a[], int size);
void reverse(char a[], int size);
void add(char a[], char b[], int c[], int size);
int main()
[Code]....
So this is my working code with sql i want convert it so i can read it from xml, basiccl i need to fill empty list with xml column BrivDat..
var connStr = @"Data Source=(LocalDB)v11.0;" +
@"AttachDbFilename=C:dbaseAdaPlus.mdf;Integrated Security=True";
List<DateTime> Holidays = new List<DateTime>();
using (SqlConnection conn = new SqlConnection(connStr))
using (SqlCommand cmdd = new SqlCommand("select * from Brivdienas", conn))
[Code] ......
I am programming a 2-D platformer video game. The stages are composed of an array (really a vector) of 16x16 px^2 tiles. I have defined a base class "Tile" and several derived classes, e.g., "Ramp", "Door", etc., which have their own attributes. The idea is that upon entering a room, the program will load all of the necessary tile data for that room into a vector. So, I have a vector that looks like: vector <Tile*> room_tiles, and resize it based on the total number of tiles in the room: room_tiles.resize(Tile_Count). I then want to read in certain info from the data file containing all of the tile information for that room. For example, if the data file says Tile 5 should be a ramp, I want to change the 5th element of the room_tiles vector to the derived ramp class. This is really where I'm having trouble. I've worked with vectors of base and derived classes before, but those were always of indeterminate size and I always used something like: (Vector).push_back(new DerivedClass()) to specify the derived class of that element. The problem is that that method only seems to work if you are appending elements to the end of a vector.
how I can do this?
How to change an enum type variable to a string type variable?
View 2 Replies View RelatedI'm trying to make a character array, and be able to custom fill it by using the scanf() function to ask the user for each character spot in the array.
Code:
#include <stdio.h>
int main() {
int i;
char character_array[11];
char *charpointer;
charpointer = character_array;
[Code] .....
And this is the output i get when i run it:
Code:
root@kali-Tulips:~# ./myown
what letter would you like in the [0] spot of the array? :
a
what letter would you like in the [1] spot of the array? :
what letter would you like in the [2] spot of the array? :
b
what letter would you like in the [3] spot of the array? :
what letter would you like in the [4] spot of the array? :
[Code] .....
Obviously I'm trying to grasp C programming and am very new. I don't understand why this isn't working, and i think its more than my lack of knowledge of C syntax. I believe the correct memory is allocated but when examined with gdb i don't find what i expect....
Code:
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
struct employee {
char firstName[20];
char lastName[20];
float rate;
[Code] .......
I am attempting to change the value of the head node in my list. I thought due to having pointer defined in parameter list I could change the address value of head node. The argument passed is a struct I did not have to use & in argument list to denote address of struct to compiler. This may have something to do with my problem. I did not include all routines called by main program just the deleteNode routine im having problems with.
bool deleteNode(struct node *head, struct node *delptr) {
node *cur = head;
node *tempNextptr= cur;
using namespace std;
while(cur) {
if (cur == delptr)
[Code] ....
i have a program that is a Mediastore and i have 4 classes. Produkt: which is a class with a few variables that i use to add products to my List.
public class produkt
{
public string Name;
public string price;
[Code]....
then i have my Lager class which i use to add my products to my list and Listbox. This is done by having 3 textfields where i say what the Name,SerialNumber and Price of the object i created should have.
In this class i also have 2 more textfields and a button that make it possible to add a quantity of the selected listbox object of my product Class. if the item im trying to add a quantity to dosent exist i get a question if i wanna add that product and it adds that product to the list. if however the product allready exist its suposed to add the quantity with the selected amount from my textbox.
Then I have my Class Kassa which is a Form with 2 Listboxes. The first listbox share the same List as the one in my Lager class and the other listbox is the listbox which i use to take items from my produktlist and put it in my checkout "basket" then i am suposed to be able to choose one of these items from my checkout basket put the amount i want of that item into a textfield called KvantLEv and press the checkout button to be able to simulate a checkout and then this selected item's quantity is suposed to be lowerd by the specified amount and is to be removed from the checkoutlistbox but this aint working... this is my checkout function so far
private void cashout()
{
produkt p = new produkt();
int a = VaruKorg.Items.Count - 1;
[Code]....
is there any variable type(or with another keyword) that we can change it's value in global scope?
View 5 Replies View Relatedis there a way to have a template class respond to missing stuff in a template type ?
Code:
template <typename Type>
class MyClass
{
public:
enum { ID = Type::ID }; // revert to 1 if Type::ID doesn't exist.
};
If the Type passed to the template has an ID member (required to be an enum or a static const int), use it, if it is missing revert to a default value.
I can use this as a simplified way of configuring how MyClass works, without requiring Type to explicitely needing to define what it doesn't care about.
It needs to be resolved at compiletime, as it determines the number of elements in member array variables.
I had the following question in my exam and received 3 out of a possible 4 marks
Here is the question:
Assume the following recursive function:
int f(int i)
{
if(i < 2)
return i;
return f(i - 2) + f(i -1);
}
Translate this function into an iterative version:
Here is my solution:
int f(int i)
{
int prev,next,final;
prev = 0;
[Code]....
I am trying to translate the following recursive function into its iterative function:
int f(int i)
{
if(i < 2)
return i;
return f(i - 2) + f(i -1);
}
This is what I tried to do:
int f(int i)
{
int prev,next,final;
prev = 0;
next = 1;
if(i==1)
final = i;
[Code] .....
I am trying to translate the following recursive function into its iterative function:
int f(int i) {
if(i < 2)
return i;
return f(i - 2) + f(i -1);
}
This is what I tried to do:
int f(int i) {
int prev,next,final;
prev = 0;
next = 1;
[Code] ....
I was talking to someone earlier about how to change the value of something from a function, and they said what was needed was to use a ** to change something, and was wondering if I could get a walk - through of what happens. I understand a single pointer well enough, but a pointer through a pointer is kind of confusing to me. Here is a simple example.
Code:
#include <stdio.h>
#include <stdlib.h>
#define SIZE 5
int add(int ** TOP, int * stack);
int *stack = NULL;
[Code] ....
Why is it that when the program prints the address of TOP in main, it is different than the address of TOP in the function? Is it because it is a different instance of TOP because it is in the function? When I put the number on *TOP, and come out of the function back to main, it then says the address of TOP is the number entered into *TOP, and am not sure why. And the **TOP ++ at the end I am thinking it increments malloc by 1, therefore bringing the pointer TOP up to point at the next element, or am I completely off base there?
I have a linked list where each node contains a pointer to a string, I'm treating the linked list as a text file and each node/string contains each line in the text file.
I have all of that working, but now I need to create a switchLine function that takes in the two line numbers and I need to switch those lines in the text file. I initially thought of switching the pointers to each the next node in the linked list such that the node order changes, but I then realized how much work that would actually take when you need to consider so many cases. So I instead thought of changing the pointers to strings. If I want to switch the 2nd and 3rd line, then I'd want to have the 2nd node in the list have its char * pointer point to the memory position that the 3rd node's char pointer points to, and vice versa.
I have a the following in a header file.
Code:
struct SortedList{
void * data;
struct SortedList * next;
struct SortedList * previous;
int (*compareFunc)(void *, void *);
void (*destructor)(void *);
[Code] ....
In a .c file, I implemented the SLCreate function.
Code:
SortedListPtr SLCreate(CompareFuncT cf, DestructFuncT df){
struct SortedList item;
item.data = NULL;
item.next = (struct SortedList *) malloc(sizeof(struct SortedList));
[Code] ....
In main.c, I try to do the following:
Code:
SortedListPtr list = SLCreate(&compareInts, &destroy);
A bunch other code that does not alter list or it's contents at all.
struct SortedList item = (*list);
void * data = item.data;
if (data != NULL) {
printf(Why did data become not null???
"); }
How come my variable data became not null anymore when I haven't altered it at all....
I have a struct called Array and I'm to create a function to create a dynamic array that's fill with randomly generated integers from 0 to 50 (inclusive) and a function to destroy the array for freeing its memory. Below the code that I have written so far.
Code:
* Struct */
typedef struct {int *pArray; //the dynamic array
int length; //the size of the dynamic array}Array;
/* Function to create a dynamic array */
Array *initializeArray (int length) {int i;
}
[code]....
It is said that variables in a function cannot be changed by another function. Only by using pointers can variable values be changed. I am writing some functions to try to prove this theory, but I can't get it right.
Code:
#include <stdio.h>
#include <stdlib.h>
int main(void){
int x = 10;
printf("default x value is %d ",x);
[Code] ......
Code:
#include <stdio.h>
void try1(int x){
printf("x in try1 is %d
", x);
x++;
printf("x in try1 after ++ is %d
[Code]...
I have the following void function devised to assign "+1" or "-1" to each element of a matrix at random. While the function does what I want, when I print the values of the matrix all are set to zero:
#include <vector>
#include "aRand.h"
#include <iostream>
void initConfig(std::vector<std::vector<int> > premat, int nL, int nN) {
int * pnRand;
pnRand = 0;
[Code]...
The function pnRand_plus returns a pointer to an array of random numbers from 1 to 100, with seed time(NULL) + i. The values printed in main are zero, despite the values printed during the function run are fine (-1s and +1s).
I need a variable that will just hold a function that I can change in the middle of the application, even to different function type with different amount of parameters ... is this even possible? At the moment I have this
struct REPLY {
string *sReply;
function<int()> special = [](){return 0;};
REPLY()
[Code] .....
And then change it back to blank function returning 0 after calling it
(reply.special)();
reply.special = [](){return 0;};
This works fine (there is no reason why it should not, right? Now, if I want to have another function, let's say
void test2(string str) {
MessageBox(NULL, str.c_str(), NULL, NULL);
}
How do I point this one to the variable special, when I want to call it like that (or something similar)
(reply.special)("test string");
is this even possible? if so, how? i tried to create function pointer (didnt compile at all) or use template (neither did this) and how to do this as I discovered functional lib just a while ago.
Instead of this:
#include <iostream>
struct Object {
int size; // Want to avoid this because size is (almost always) constant
Object (int s): size(s) {} // for every Object subtype.
[Code] ....
I want this:
#include <iostream>
struct Object {
virtual int getSize() const = 0;
};
struct Block: Object {
int getSize() const {return 5;} // always 5, except once in a blue moon it may change
[Code] ....
The Decorator Pattern works (getSize() can then return 6) but it is a poor choice for my program because it will cause more problems (due to many containers holding its old address, among other things. Any way to achieve this without any change of address, and without creating new storage somewhere, either inside the class or outside the class (too much responsibility to follow that stored value for the rest of the program just for this rare change, and creating a data member uses up too much memory for the many, many Block instances)?
I have a Polymorphic class and some child classes, of which I need to make multiple instances of, using a list container. I've set the key type to be a unique pointer of the polymorphic class, and the values of each element pointing to a New Child instance, like so:
std::list<std::unique_ptr<Polymorphic>> polymorphic;
polymorphic.push_back(new Child(foo, bar));
The only problem is that when I try to push_back a new element, I get a compiler error, saying "No instance of overloaded function".Should I try and create a pointer object on it's own and push back that object as an element, it will work fine:
std::unique_ptr<Polymorphic> polym(new Child(foo, bar));
std::list<std::unique_ptr<Polymorphic>> polymorphic;
polymorphic.push_back(polym);
Is there some way I can push a new Child instead of having to create a Polymorphic pointer object and pushing that?
I am trying to use a class Student and declare it as a list type. I can pushback but without changing the List.h or Node.h how can I print the data in list2?
Node.h
#ifndef NODE_H
#defineNODE_H
#include <string>
[Code].....
So I query out data from multiple tables and I put it as anonymous type. But since I need to get the remove function going, my datagridview has to get datasource from a bindinglist, not just a list. What could I do from this situation? I already checked: [URL] but intellisense doesn't pick up the .ToBindingList() function for my query.
View 3 Replies View RelatedIm trying to do something like this:
private List<Calm> calm = null;
private List<Horror> horror = null;
private List<Battle> battle = null;
[Code].....
I want with lists[0][0].Name to get the Name variable from the first item of the list calm, but this doesnt working, is there any other way to do it?
