C++ :: Splitting Linked List Into Two Separate Lists
Feb 14, 2013
I've been given a ton of code (5 files worth) that does various things with a linked list. I'm supposed to add a function to split this list into two separate lists by testing whether or not each number is <,=, or > a certain element. I am completely lost and don't understand linked lists at all. I'm also a bit lost on pointers since it's been almost a year since I've looked at programming, but I could probably figure that out if I could just get this linked list thing down.
Here's my SplitLists function so far:
void UnsortedType::SplitLists () {
// Pointers for each new list
NodeType* list1Ptr;
NodeType* list2Ptr;
[Code] ....
In other places in the code, I have GetNextItem, ComparedTo, PutItem, and ResetList that were already given to me.
I'm trying to develop a program that stores a list of hw assignments in the form of "Date,Assignment name,grade". I have functions that add,remove, and delete from a list, but I would also like to search and delete a particular date found in the list. From here, split - Splitting a string in C++ - Stack Overflow I've tested Evan Teran's method to split a string, but I'm unsure of how to implement it in my code.
List.h Code: #ifndef LIST_H #define LIST_H #include <string> using namespace std; class List{
I'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.
Write a program that creates a forward linked list of at least 20 elements, where each element holds a random integer between 0 and 99. Print the list.
Write the function "returnMiddleList" to find the middle element of the linked list in one pass. Print the integer value of this element and the position of this element (starting at zero) in relation to the head (where the head = 0, the element pointed to by the head = 1, the element pointed to by the previous one = 2, etc).
Split the list in half at the middle element to create two entirely separate* linked lists of near equal size (+/- 1) and print the two lists. Modify the "returnMiddleList" function to accomplish this, returning the head of the second linked list and setting the link of the element pointing to that head to null. Then print the two sums of the integers stored in the elements of both lists.
Sort the two lists from least to greatest and print them out (printing at this step is optional depending on the sort approach taken). Then combine the two lists while sorting them again from least to greatest and print out the new list. (HINT: you can subdivide the lists further and sort them on a scale of one to two element lists before sorting and combining the first two unsorted lists. What is this sort called?)
I have got #1 and #2 working, but #3 and #4 is where the issue is beginning. When I split my link list into two lists and print the individual lists out, my first link list prints out 9 numbers when it should be printing out 10 (the 10th number somehow disappears?), but when I do the sum of the first list right after that, the number that has disappeared gets added in the sum! I do not know why it is disappearing, and this is one issue. Another issue is in the second list, a random "0" gets added to the list and one of the numbers is lost. My last issue is about #4 as the merge algorithm I have used does not seem to work (I am merging the list together while sorting them, but I am not using a recursion sort because we have not learned that yet).
#include <iostream> #include <stdlib.h> #include <time.h> using namespace std; struct nodeType { int data; nodeType *link;
I have been looking everywhere, but the only place I have seen it done is Objective C. The Question: how do I split a string, input by the user, into an array of characters? No code shown because I know no commands that do this.
In our homework assignment it states to, "write a set of dynamic linked lists" and so on. Now, the problem I'm confusing myself is at the storage inside of each node. To my understanding, each node contains the prev and next nodes, but also a pointer to the data, in this case being a string. He has asked us to manage these strings as rows of chars such as
char[0] = c // first node being addressed here char[1] = a char[2] = t char[3] = char[4] = d // second node starting here char[5] = o char[6] = g char[7] =
I have written my code where each node is holding a string, not separated as shown above... my question is to how you can build your doubly linked list where each node is being address a set of chars.
I'm trying to do is let the user type in something like A654321 (note: these are ALL the characters, i.e. 'A', '6', '5', '4', etc..) Then I just want to display that current number back to them and I am getting some weird pointer memory allocation error..
#include<iostream> using namespace std; //To rename data-type "int" or integer to "element" (Both are equivalent).. typedef int element; //To declare an appropriate SENTINEL. char const SENTINEL = '#';
[code]....
It seems like the first part that it bugs out at is in my Clean(); function..
Unhandled exception at 0x01383FBB in VegMe.exe: 0xC0000005: Access violation reading location 0xCCCCCCD0.
It doesn't like head = head->next; ?Also, ignore the ReverseList(); function, it is not being used as of now.
Error 1 error C3867: 'std::basic_string<char,std::char_traits<char>,std ::allocator<char>>::size': function call missing argument list; use '&std::basic_string<char,std::char_traits<char>,st d::allocator<char>>::size' to create a pointer to member.
I am having some trouble getting a 3d array of pointers to link up with a linked list for each of the array elements. the 3d array of pointers is declared like this:
Code:
struct particle *cell[MAXCELLS][MAXCELLS][MAXCELLS]; and there are linked lists declared like this: Code: struct particle { /* structure for particles */ double sw[3]; /* square well components */ double hs[3]; /* hard sphere components */ double u[3]; /* unit vector for rotations */ struct particle *link; };
I want to get the array pointers 'cell[x][y][z]' to point to the first observed particle in a function next to main, something like this:
Code:
void generate_list(){ int i,j,k,l; /* determine the number of cells to decompose the simulation box in each of x, y and z directions*/ int(cells_x) = floor(boxX/cell_size); int(cells_y) = floor(boxY/cell_size); int(cells_z) = floor(boxZ/cell_size); /* initialise the array of pointers to NULL */ for (j=0;j<cells_x;j++){
[Code]...
I am getting a pointer type cast error when I compile "assignment from incompatible pointer type",
I have to write a program that reads from a text file, which contains a list of stock hourly prices and the company names. Something like this:
78.52 82.56 75.10 71.97 Water Company 22.40 25.68 21.37 22.96 Mega Shipping Inc
Each company data will be kept in a structure that contains: a pointer for the name, an array of the prices, and the average price for the day. The structures will be kept in a linked list. Each node structure will contain a pointer to one company data, and a pointer to the next node structure.This is all I have so far..
We have to sort the nodes alphabetically. My question is, how do I read the data from the file one line at a time, and insert them alphabetically one by one?
I'm trying to compare a single value with a value from my Linked list and if they are same, I want to add the value from the list to new list. In other words I want to create a new List with values with the first one. Here is the code that I made, but it's not working.
This is the code with which I search in the first list for a node with a value. In the main() function I have A.find_city(), so it can start from the start_pointer from the first list:
void List::find_city() { List *temp1; int b = 0; char city[20]; cout << "Enter city: "; cin >> city; temp1 = start_ptr;
[Code] ....
This is the code with which I add a node to the new list:
I have this code that I need to memorize for my final. Memorizing code is easy for me, but I'm trying pretty hard to fundamentally understand the functions, and what they are doing (even using pen and paper, to draw and trace).For example, in the push function below, I understand everything, except why I'm setting ptr = p. I feel like p should be equal to NULL, then the next node I push should be equal to p, etc.
Stack & Stack::push(double x) { Node * p = NULL; try { p = new Node; }
[code].....
Also, are LL Queues that hard to implement once you can do them w/stacks - That will probably be something I have to code for my final, as well. Below is the full code for my Stack class.
#include <iostream> #include <string> #include <stdlib.h> using namespace std; class Stack }
A static method named readFromFile that takes a C-string as the first parameter, and an orderedLinkedList<MemberDO> object as the second parameter. The first argument is the filename that contains data for existing members. This method should read the data for each individual member from the input file (one line of data per member), create a new MemberDO object, and insert this object into the linked list specified in the second argument.
How do I take the second parameter in, do I need to create the Linked List first? Here is the code I have so far
#include<iostream> #include<string> #include <fstream> using namespace std;
So I have a Class named Subject, wich I used linked list to keep the objects. Now I have another Class called Tests which I should register a test by the Subject class, so I made a search like this:
List obj; //it's the object to access the List class, which manipulates the //nodes from Subject.
obj.currentPtr=obj.firstPtr; while (obj.currentPtr!=NULL) { if(obj.currentPtr->nameSubject==value) //searching if there's a return obj.currentPtr; //name equal to provided obj.currentPtr=obj.currentPtr->nextPtr; } return 0;
I've made a similar process for Subject. But in this when I access the firstPtr, it's shown to be 0, once I have already the list of Subject and it should not be zero. What's wrong?
The objective of the project is to become familiar with linked lists by writing a series of basic functions that allow us to manipulate a set of linked lists. I've completed all of the functions except for one.
The function I am stuck on is supposed to do the following:
concatenates list1 and list2 to form a new list, and returns a pointer to this new list;
Note: new list contains copies of all nodes in list1 and list2 */
The assignment is apparently pretty classic: given a starting state and a goal state, show the optimal path to solve a 3x3 sliding puzzle.
I have the code in place.Where I'm experiencing major issues is in maintaining two distinct linked lists. One should contain the frontier of the A-star algorithm and the other records the optimal path. In execution, however, it seems that only one list is in local memory in any one function. Therefore, when my function recurses, the lists begin to get confused and the whole algorithm veers off course.
Here is my structure definition in list.h:
typedef struct node { int value; int state[3][3]; struct node *next; } Node; typedef struct list { int count; Node *first; } List;
Here is my List_create function in list.c (do I need malloc here?):
int main(void) { List open; List closed; List_create(&open); List_create(&closed);
Here's the general flow of the program, without posting a wall of code: both lists are passed to another function in main.c, expand(), with this line:
expand(current, gState, &open, &closed);
The lists are later passed from expand() to another main.c function, generateOptions(), in this line:
generateOptions(&array, goalState, open, closed);
generateOptions() returns back to expand(), which recurses on itself with the first item in the open list and continues the expansion:
expand(open->first, goalState, open, closed);
Strangely, the open list prints out correctly before generateOptions() returns to expand(), and the closed list prints out correctly after generateOptions() returns to expand(). But when I try to print the open list in expand(), I'm instead given the closed list. Like I said at the outset, it appears that only one list exists at a time!
I am having to write a program that takes 2 sorted linked lists (x and y) and merge those to sorted into a third one (z). This has to be done via recursion. I think I am close but there is a logic error.
