I create some code that assign values to a dynamic memory structure. I'm not sure why one code works and the other crashes when it assigns a value.
Working Code
#include <iostream>
using namespace std;
struct WorldOjectCollisionMap
{
[Code].....
have to do an election program in C.
There are 7 candidates and 365 votes in total. I need to do this using an array of structures. I need to read from a text file each of the names of the candidate and the number of votes they get. At the end i need to output the winner of the election.
Here is a sample of my code so far
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
struct candidates {
char name[20];
int votes;
[code]....
Here is a sample of my text file:
Robert Bloom
John Brown
Michelle Dawn
Michael Hall
Sean O’Rielly
Arthur Smith
Carl White
1 2 4 5 1 2 3 4 4 1 2 3 7 4 4 5 3 7 7 7 7 7 7 7 7 7
Each candidate gets +1 vote for their number electionCandidate[0] for each one he gets one vote and so on for the rest. 365 voters in total.
I was able to input the name for each Candidate from the text file. Now the problem is putting each vote to the corresponding candidate. Also any vote that is above 7 is a spoilt vote which i am trying to count in the above code. The code compiles but it crashes.
I am using while(!feof) but it seems that its not working or this is not the correct way.
i'm implementing a playerclass for a game.. in the game there are multiple player types, weapons ect.. i just wanted to turn my players weapons into a dynamically allocated c_str. once i added my: Destructor, Copy Constructor and Overloaded Assignment Operator. My initial values became corrupted and i cannot fix them.
Player2.cpp
#include <string.h>
#include <iostream>
#include <cstdlib>
#include <iostream>
#include "player2.h"
#include "dice.h"
#include "gamespace.h"
[code]....
See the simple code below. The compiler gives message:
assigning to type "char[20]" from type "char *".
I've tried everything else that seems reasonable but none works. How can I assign string Hello to the structure member?
Code:
int main() {
struct strc1
{
char msg1[20];
char msg2[5];
}
talk;
talk.msg1 = "Hello";
}
I'm a C beginner trying to assign struct member values to other struct members to create a list.
I've tried dot notation, pointer notation, strcpy, memcpy, memmove and normal assignment.
Nothing has worked.
cust_list.h
I can assign values to pointer character array like this...
Code:
char *array[4]={"abc","xyz","dgf","sdt"} ;
but the case is i don't know how to assign strings through key board ???? with using gets ,getchar or other suitable function
My game is a sort of RPG with stats, money etc. I just recently added a save/load system using writing to a file. I initially got writing to a text file to work, then I got loading to work too.I eventually was able to read numbers from the file and assign them to integer variables in order.
My issue was I wanted to check if a save file existed, if it did, load it up, if it did not, go to character creation. I had a lot of trouble with this and after trying different code snippets to work I finally got it to check if a file existed, and execute the appropriate code.
My issue now is my code USED to go through each entry and assign variables in order.
Like the first number in the text file would be for the variable money, and it would read it, assign to to int money and scroll to down to the next variable for player strength, assign to to playerstr variable and so on. After making the tweak for loading it no longer functions like this, and makes the last entry in the text file the value for everything.
Here's my code:
Save Code:
{
ofstream savegame;
savegame.open("C:/Sounds/savegame.dat", ios::trunc);
savegame << money << endl;
savegame << playerstr <<endl;
[Code]....
I barely get how this code works, how can I tweak it to go through the file in order and assign variables one at a time?
At the current moment, it assigned the playerstr value to both money and playerstr int. But the save file being created lists the correct values in order.
I'm working on a Dijkstra's algorithm with a fixed graph. My question is, how should I go about assign distance values to the graph. The user can start from any node.
View 4 Replies View RelatedAfter i set the value in the first structure owners name, i set the cats name equal to it. but when i change the value in the first structure it doesn't change the value in the second structure.
So i need the dogs owners name to be equal to the cats owners name
So if i change the value of the dogs owner it also changes the value of the cats owner.
Code:
#include <stdio.h>#include <stdlib.h>
#include <string.h>
//stucture
struct structDog {
[Code] ....
I need to assign unique integer values to words in a dictionary that have the same alphabets, for example 'act' and 'cat' should have the same integer value. Would just adding the ascii values of the letters be sufficient?
View 1 Replies View Relatedis it possible to make something like that?
struct type_name
{
char Status[i];
string Status[j];
.
.
} object_names;
The problem is I dont know how many statuses my object will have. Is it possible to make it in an dynamic array?
I have declared a global variable as pointer. The program performs certain number of iterations. After every iteration, the size of memory required for the pointer changes and this pointer variable is to be accessed by different functions. Now, here is my doubt:If I allocate the memory for this global variable in a function, will the contents of the memory be lost once I exit that function. In my opinion, it should not be the case as the dynamic memory allocation takes place in "heap" and should not be affected by the call of functions.
View 4 Replies View RelatedI am new to C++ language and I am still learning.I'm doing basic stuff to better understand dynamic memory. I was wondering why I keep getting memory issues.*/
#define SIZE 15
class word {
char* str;
public:
[code]....
i can't implement trie with dynamic array .the problem is in this line i think :
Code:
childs_size = (node_p -> childs_value_p)[0] + 1; here is my code : Code: #include <stdio.h>
#include <stdlib.h>
#include <string.h>
struct trie_node {
unsigned char *childs_value_p; // pointer to an array of child nodes value
struct trie_node **childs_ptp; // pointer to an array of child nodes pointer
struct trie_node *failure_node_p; // pointer to failure node
[code]...
i could write this code with binary tree instead of dynamic array but need a large amount of memory for about 13000000 strings of length 16 . is there any better solution with lower memory usage to implement trie ?
I have recently bought a copy of "Jumping into C++" and have come to chapter 14 ( dynamic memory location) and have a question.
On page 153-154 an example of dynamic allocation is given for array's of int. How would the code look like for strings or structs ?
The allocation was given by:
Code:
int *growArray (int* p_values, int *size)
{
*size *= 2;
int *p_new_values = new int[ *size ];
for ( int i = 0; i < *size; ++i )
{
p_new_values[ i ] = p_values[ i ];
}
delete [] p_values;
return p_new_values;
}
Sample Code I tried to use this for an array of structs but failed completely....
I used the following struct Code:
struct user{
int days;
string name;
};
and the allocation function (which does not work):
Code:
struct user *growarray (struct user *p_values, int *size) {
*size *= 2;
struct user *p_new_values = new struct user[ *size ];
for ( int i = 0; i < *size; ++i )
[Code].....
I am creating a connect 4 game using dynamic memory allocation the question is;
Write a two-player game of Connect Four where the user can set the width and height of the board and each player gets a turn to drop a token into the slot. Display the board using + for one side, x for the other, and _ to indicate blank spaces.
I have created the board. However I am unsure as how to make a start on getting the players to make moves.
Code:
#include <iostream>
using namespace std;
char **create_table(int width, int height, char blank) {
char **p_p_connect4 = new char*[height];
for(int i = 0; i < height; i++) {
p_p_connect4[i] = new char [width];
[Code]....
I'm having problems with this code:
#include <iostream>
using namespace std;
class Foo {
public:
Foo( int n );// Constructor
~Foo();// Destructor
int *ptr;
int N;
[Code] ....
I'm using Visual C++ 2008 version. The problem arises at the end, after the sentence 'system("pause")' is reached, which makes me think that the problem happens when calling the destructor. The destructor is called twice, the first time it's called is in the function print. The problem seems to be that the destructor can only be called once.
I know I can avoid this situation by defining the function print like this:
void print ( const Foo &f )
...
but I would like to know if there is some way I can do this keeping the definition that I've provided.
So I'm trying to wrap my head around dynamic arrays, and I've finally figured out how to build one, using
int arraysize = randomnumber;
int* arrayname = new int[arraysize];
Now, how to delete the array. Can I free the whole array from any scope in my program using a simple line like delete arrayname;?
Also, since I'm working in heap, I can't rely on the debugger to show me when I'm doing something wrong, If I create a struct such as :
struct twoints {int one, int two};
and then try to create a dynamic array of said struct using
int arraysize = 5;
twoints* arrayname = new twoints[arraysize];
Am I basically creating an array of 5 two ints?
//is it the same as doing this?
twoints arrayname[5];
In my platform, Windows 7 Ultimate 64 bits with Service Pack 1 over a x86-64 AMD microprocessor, AMD Phenom II 1090T X6, with a total of 4 GBytes of RAM memory), one C++ program can only allocate up to 2 GBytes of dynamic memory (using operator new, so Heap memory).
In am using the IDE Microsoft Visual C++ 2010 Express Edition to compile my C++ program and generate the executable file (for Win32).
In my system, there are much more available memory than 2 GBytes (yet remain 1 GByte of RAM memory and the virtual memory), so, Why can't my C++ program allocate more than 2 GBytes of memory? Do I need to configure something in the IDE to allow more memory to the program?
I created a class (let call it X) which contains the structure to store the data from my data base. Them I have a class (call Y) which will contain a list for each row in my data base. Third, I have a class with thousands variables (Z). What I am trying to do is to take the list of objects (Y) that contains the data to initialize Z. What I want to now if I can do something like that.
Imaging that one of my rows contain the following data:
Type Nameofvariable etc...
"static const double; MNFAIL ; 0; 0; 0,25"
In my list I have a node with contain this data
I want to use the field Nameofvariable to initialize the variable called MNFAIL contained in my class Z.
Is it possible in C++
I am fairly new to dynamic memory allocation and I keep getting a segmentation fault in this code of mine. This is what the method should do:void sort StringsByReversePoints(char **myWords): This function sorts the char* values (i.e. strings) of myWords in descending order of point value by calling getWordPoints as a helper function and comparing adjacent words. This simple (but inefficient) sorting algorithm starts at the beginning of myWords array and sweeps to the end comparing adjacent values and swapping if they are out of order. After N (length of the array) sweeps the array is fully sorted. Note that efficiency can be improved by a factor of 2 by shortening each successive sweep by one, since the first sweep will have guaranteed the minimum point value word is the last element of the array, the next sweep guarantees the last two elements are correct, and so on....Additionally, if a given sweep results in zero swaps then the array is sorted and you can return immediately.
View 5 Replies View Relatedwe are currently covering double pointers and memory allocation. Currently getScrabbleWords is not working. when I compile with commented code (Main() works fine) I get a segmentation fault.
This is the purpose of getScrabbleWords:
char **getScrabbleWords(char **allWords, char letters[]):
This function takes an array of char* values (i.e. strings) representing all the words read from wordlist.txt. Each of these words is tested by callingcanWeMakeIt as a helper function, and pointers to the words that can be made are put into an array, myWords. Note, copies of the words are not made! In order to indicate the end of myWords, we terminate with a NULL pointer. Thus, if N words can be made from letters then myWords should have length N+1.
Why cant a dynamic memory allocation work with references? I was told that references work with const pointers deep down so shouldn't this be legal code?
int &&a=new int;
My compiler says that a entity of int* cannot be used to initialize a entity of int&&?
Does that mean that the compiler thinks of them as different types except deep down a reference is implemented with a pointer? Is this right?
I am using a pair of pthreads that call a pair of functions for ping-pong dma data transfer that are used in a loop for data transfer from an acquisition board. For a large # of waveforms, I ultimately run out of PC memory and the program stops. At the end of each function I use the delete[] command to clear memory for reuse, but the pointer appears to advance by the array size used for the transfer until the location exceeds the 2 GB I have for memory. I can see this happening using the Task Manager performance button time plot and window of total memory used continuing to increase to the limit. The culprit for one of the functions (2nd) is:
unsigned char* dataBuffer2 = (unsigned char *) (pci_buffer2.UserAddr);
where pci_buffer1 and 2 have been set up and allocated in main. I also had the following line in each function process:
double* Rin = new double[length];
and it used up memory twice as fast. When I transferred the last line to an area just prior to main and used a constant 1024 for length, the program ran twice as far before exceeding system memory, so it appears that both lines were forcing new memory assignments and moving the pointers accordingly. In addition to using the delete[] command to free memory unsucessfuly at the end of each function procedure, I ended up closing the memory at the end of each procedure, then reallocating it again with the idea that the pointer would be set back to the original value, but it still seems to icrement along. So, neither approach appears to allow reuse of the memory because the pointer continues to march along. Using Visual C++ 6.0 to compile.
Suppose:
cin >> number;
pointer = new type[number + (rand()%number);
So, I wont know the memory allocated for pointer. How can I check it in all OS?
I'm trying to free allocated memory for structure. It seems like free() gets only pointer and not regular types . my question is basic and simple – is passing pointer to free() frees the pointer or the variable it points at? or both?
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