Linked lists seem to be the most erroneous and most frequent thing I use and post about nowadays. I've been wanting to handle data structures in my own library of functions, but I'm not sure how to imitate polymorphism without too many ambiguities. I could just pass some character or string value to represent a type, but I wanted to see if there was actually something more elegant I could use before I dive in.
View 4 RepliesI am trying to create a linked list and then reverse it. So far I have created the link list however I am having difficulties figuring out the steps to reverse it. What is the logic behind reversing this linked list. I am not able to use recursion. I am supposed to create a copy of the linked list with the nodes reversed.
Code:
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
struct charNode {
char data;
struct charNode *nxtNode;
};
[Code]...
I'm trying to create a function that allows insertion anywhere in a linked list...here is what I have so far but am a bit confused on where to go from here
Code:
void llAddAtIndex(LinkedList** ll, char* value, int index) {
LinkedList* newNode = (LinkedList*)malloc(sizeof(ll));
newNode = *ll;
LinkedList* prevNode = (LinkedList*)malloc(sizeof(ll));
[Code].....
What is the best / most efficient way to load polymorphic data from a file? I thought you could have an enumeration and for each item to load from a file you could have an integer at the start specifying the type of data, but I think there must be a better way I'm just not sure what.
Example of what I mean:
//The syntax isn't really that important for explanation
class base;
class a: base, b: base;
enum polymorphicType {
A,
B
};
and in the loading code you would have (this is the bit I think could be improved):
polymorphicType t;
File >> t;
if(t == A) {
newObject = new A;
} else if(t == B) {
newObject = new B;
}
I think there is probably a more efficient/better way of doing this I am just unaware of it.
Code:
void loadData(fstream& fin, nodePtr head){
if (fin.eof()) {
return ;
}
else
[Code] .....
This is my function and it is not working.
Code:
#include <iostream>
#include <fstream>
#include <cstdlib>
#include <iomanip>
#include "contacts.h"
using namespace std;
[Code] ....
Lines 29-32 I have a good feeling very wrong. Now I have never learned how to do this and my book covers nothing over this. I just took my final in C++ so this is not homework. I am trying to get better before Data Structures start next month.
I am trying to write a program which involves linked list. i have to create a method called add_aa( str ). I am reading from a text file. in the text file it just contains the values for str. what I am trying to do is create the method add_aa( str ) and add what corresponds to str from the file. here is what the output should look like. and what i have is very basic. here is what i have
inline void LList:: add_aa(const string _str) {
cout << " p = " << std::hex << p << std::dec << '
';
}
I'm thinking using a for statement, but how to incorporate it
Attached Images : sample.JPG (35.2 KB)
I am trying to read in a text file and add strings from it word by word into a Linked List. I'm fairly new at C and don't quite understand pointers. I've had a few different errors just messing around with it, but now I'm getting an infinite loop within my main program.
Code:
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
struct listNode { /* self-referential structure */
char data[50];
struct listNode *nextPtr;
[Code] ....
When I run my full code, it prints 12345ooooooooooooooooooooooo...etc. In my test file the first word is "Hello" so that's where the infinite 'o's come from. If the outer loop is the one that is infinite, then wouldn't the second while loop also execute more than once? What I mean is, why is the second print statement the only one that repeats itself?
I've been trying to read a .txt into a linked list in the attached code. I'm running into problems, specifically I'm getting errors on line 41 (curr->word=charTemp. I'm trying to set the word array equal to the charTemp array. I've tried strcpy with no luck .
Code:
#include <stdio.h>#include <stdlib.h>
#include <string.h>
//Struct for linked list
typedef struct node {
char word[25];
struct node *next;
} node;
[Code]...
I'm trying to open a file (contains member information) and store the information in an object, which is then inserted into a linked list. However, the current code just leaves a blank command window hanging with nothing happening.
main.cpp - [URL] ....
MemberProf.h - [URL] ....
MemberProf.cpp - [URL] ....
LinkedList.h -[URL] ....
I have a program and function i'm having an issue understanding. Here is what it's doing in the main.
int main() {
orderedLinkedList<MemberDO> memberList;
MemberDO::readFromFile("Member.dat", memberList);
return 0;
}
So it is creating a linked list object using the MemberDO class type which has a int, string, char and double. Then it will call the readFromFile static function in the MemberDO. So this is where my problem is I have this function
void MemberDO::readFromFile(char *fname, orderedLinkedList<MemberDO>& list) {
}
How do I read in each individual data member from the input then create a new MemberDO object and insert the objects into the linked list specified in the second argument list?
Here is the MemberDO class declarations
class MemberDO {
private:
int key;
string lastName;
char firstInitial;
double dues;
[Code] ....
I'm not sure why my destructor isn't working..
typedef struct Node;
struct Node {
char data;
[Code]....
I have a data file that looks like:
111111111
Lisa
Porter
3
ENEE 114
CMSC 412
ENME 515
333333333
Alex
Simpson
1
CMSC 412
***
In the form student ID and then first name last name number of courses and finally the course code(s). Im currently attempting to read these into linked lists with the following code:
#include<stdio.h>
#include<string.h>
#include<stdlib.h>
struct CourseInfo {
int courseID;
char courseName[30];
[Code] ......
I get no errors or warnings however when i print this out i get:
111111111
Lisa
Lisa
Porter
3
ENEE 114
CMSC 412
ENME 515
And then the program crashes. So i know that for some reason the problem is the
fgets(rootPtr->FirstName, 22, p);
But I do not know why because it seems to work for the other fgets. I also want to know why the while loop never runs and it crashes instead.
I have to initialize my stack (done by linked list) and I have a txt file for that. It looks like
123 Mike Smith 3.5 BA
124 John Weasly 2.9 CD
Here is what I have done so far:
However, I cannot reach any result.
Let me update:
123 Mike Smith 3.5 BA
124 John Weasly 2.9 CD
Here is what I have done so far:
struct Record{ //struct
float number;
char name[10];
char surname[10];
float GPA;
char mark[SIZE];
Record *next;
};
[Code]...
Why program crashes when reading linked List from file?
#include <iostream>
#include <fstream>
using namespace std;
struct link{
int data;
link* next;
[Code] .....
I am having difficulty calling the constructor in interface portion of my program. I get the error: no matching function for call to ‘Node::Node(int, NULL)’ when I try to call it on line 26 within the main function.
code:
interface: [URL]
implementation: [URL]
main file: [URL]
I have been attempting to store mathematical functions in a file by parsing them into a linked list with a variable sized char ** array as my storage device. I have ran into problems with the memory management detail. The program crashes before output is flushed to the console, so printf() wasn't a debugging option. Neither is my actual debugger, since it seems to get a SIGTRAP every time. I have my warnings turned all the way up, but no errors or warnings are appearing. The part I know works is the actual code that opens the file and gets a line from the file. As far as the two functions that implement the linked list, that is most likely where the problem lies. My current attempt is basically to store the size of the dynamic array in the structure and keep resizing it until there are no more tokens. Then I will store the number of elements of the array in the structure and move on to the next node.
Here is my text file I use :
Code:
sqrt( 25 ); pow( 6 ); sin( 2 );
pow( 4 ); tan( pow( 2 ) ); Main.c :
Code:
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
typedef struct file_data
[Code]...
My program takes in an input file from the command line and converts the string from the file into a linked list and then depending on the command it will manipulate the string to either reverse the list, print the list, or take a character out...I'm having trouble taking a character out, my code compiles fine but doesn't change the string at all
Code:
#include <stdio.h>
#include <stdlib.h>
#define SIZE 1024
[Code]....
I am doing c++ program to read coordinates from text file into double linked list. Everything seems to work perfectly but it stores only 298 items in linked list. Im not sure if my code is wrong or I missed something. On the debugger length of list is over a 1000 but like I said it print outs only 298.
View 2 Replies View RelatedI'm having a problem in my Library assignment, this section of my code is for reading in books saved in a 'book.dat' file on my desktop and inserting them into the linked list. It kind of works, but say if there is two books in the file, it only saves the second book twice.
eg in book.dat:
123 book1 Tolkien 2009 0
111 book2 Rowling 2009 0
So once these are read in, and I call my method displayAll(), it would display the second book twice..
void importFromFile(FILE *fp) {
struct book *aBook;
struct node *aNode;
aBook = (struct book *)malloc(sizeof(struct book));
[Code] .....
I have a code able to import a file containing words and numbers to a linked list, but I also need to sort this linked list alphabetically. I've done research on this involving bubble sorting, but no explanationcan achieve this objective.
Below is the code that can only put the file into linked list:
Code:
#include<iostream>
#include<conio.h>
#include"U:C++WordClass2WordClass2WordClass.cpp"
#include<fstream>
#include<vector>
#include<string>
using namespace std;
[Code] .....
In the program I'm writing, I'm creating a linked list of students with individual data read from a file. At the moment, I have written two functions to accomplish this; one that creates a student node and fills it from a line file, and a second that calls on the first to create a linked list. It seems to work fine except for one thing; It seems that EOF is being reached first, but the function continues on anyways? Here is my code so far...
Code:
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
struct student
// Declaring student structure globally.
[Code] .....
And here is what the input file would look like...
Thui Bhu, 100, 90, 80, 100, 89, 99, 88
Ariana B. Smith, 90, 90, 100, 100, 99, 100, 95
Emily Gonzales, 100, 90, 100, 70, 78, 78, 80
Jennifer L, 80, 90, 90, 100, 89, 99, 85
Maria Jones, 65, 72, 77, 68, 62, 70, 65
Bill Gates, 60, 54, 38, 62, 65, 60, 50
Escobar Morris, 83, 77, 88, 76, 79, 72, 76
Anne Latner, 80, 80, 85, 95, 90, 95, 98
John Doe, 45, 87, 88, 89, 67, 96, 79
And here is what the output is...
EOF
EOF in create_record
Thui Bhu: 100 90 80 100 89 99 88
Ariana B. Smith: 90 90 100 100 99 100 95
Emily Gonzales: 100 90 100 70 78 78 80
Jennifer L: 80 90 90 100 89 99 85
Maria Jones: 65 72 77 68 62 70 65
Bill Gates: 60 54 38 62 65 60 50
Escobar Morris: 83 77 88 76 79 72 76
Anne Latner: 80 80 85 95 90 95 98
John Doe: 45 87 88 89 67 96 79
Press any key to continue . . .
I'm completely new to C, and I don't know how to create a library using Xcode.
View 5 Replies View RelatedI'm trying to write a function that takes two linked lists and creates a third one with only the common elements.
It assumes the first list (the caller) has no dups, but it doesn't seem to be working. The program doesn't crash, it just hangs when it is supposed to display L3 (the third list)..everything else runs and is displayed fine.
template <typename T>
LList <T> LList <T>:: common (LList <T> &B)//common fct
{
Node <T> *hunter1 = Head;
[Code]......
Anyway, I have an assignment in which I'm supposed to create a program to be used in a library. Basically a database storing all books currently outside the library along with who and when borrowed them. It also says I should use single linked lists.
Now, I've got a general idea of how to make it work but I've stumbled upon a problem. Since the program has to write all the data put into the database in a file and be able to tell the user whether a book has been kept too long by the reader, I figured I'd implement the struct tm to convert the date when the book was borrowed (or rent, whatever, English is not my first language ;p) into UNIX time.
Then, when I'd like the program to tell me which books are being kept hostage by the readers the program would look for a certain record (like a string inside a certain struct) and compare the date inside that record with current date and then the result of this comparison would be compared with a given, defined time limit. Although this is all a different kinda function, it's a bit simplier, I guess, and I think I'll work it out. However to get there at all I need to be able to store the data correctly and there is a problem, which I'll explain on the other end of the code .Here is the code I came up with:
Code:
#include <stdio.h>#include <string.h>
#include <stdlib.h>
#include <time.h>
int DisplayMenu();
int ReturnToMenu();
int AddBooks(char *filename);
[Code] ....
So, my problem is as follows: the date seems to be stored alright, but it's wrong. For checking I had a Code: printf("%d", mktime(&date)"); added and it returned "-1"... As I said, I'm relatively new to coding/programming and my knowledge is rather rudimentary.
By the way: I had one more gremlin haunting me on this one. Namely at the begining of the input to the AddBooks function:
Code:
int flag = 0; do
{
printf("Please type in the book's title:
");
gets(newbook.title);
if (strcmp(newbook.title, "") == 0)
[Code] ....
The do while loop is to ensure 'unempty' input. Without this loop however, the program would display the message "Please type in the book's title:" but it wouldn't wait for input. It's simply jump to the next printf and wait for input then... I figured it might be becuase it took the 'Enter' that was somehow still in the memory after the user confirms his selection in the menu... It's just a guess, though.
I'm trying to find a C library for automating mouse clicks and keystrokes, something like the Python package AutoPy would be ideal.
Might have heard of Auto-it [URL] ...., which automates GUIs in Windows. Something like that would also be good, but my main OS is Linux.
I'm not sure whether it would be possible to create a shared library from the C source code in autopy.