Messages Order C++
Problem Statement :
In real life applications and systems, a common component is a messaging system. Thea idea is that a sender sends messages to the recipient. The messages might be sent for example over the network. However, some network protocols don't guarantee to preserve the order of sent messages while they are received by the recipient. For example, if someone sends a text messages hello, hi and what's up, they might be received in the order what's up, hello, hi. In many systems the expected behavior is to preserve the order, so the order of sent messages is the same as the order of received messages.
In this problem, the task is to implement a software layer over the top of a network protocol sending messages in arbitrary order, in such a way that the sent messages are printed by the recipient in the order they were sent.
In the template code below, there are implementations of classes Recipient and Network.
Your task is to implement classes Message and MessageFactory according to the below specification:
Class Message is required to store a text value of type std::string and provide a public getter const string& get_text() which is expected to return this text value. Besides that, it should implement the < operator that will be used in fix_order() method of the recipient to fix the order of received messages. Feel free to implement any other methods and class/instance variables. In particular, you can implement any additional constructors, but make sure that you provide an empty constructor, i.e. the one without arguments.
Class MessageFactory is required to have an empty constructor, and implement a method Message create_message(const string& text) that is expected to return a Message object storing the value of text argument. Feel free to implement any other methods and class/instance variables of this class.
The locked code template will act as follows. First, it creates objects message_factory and recipient. These objects are of types MessageFactory and Recipient respectively. Then, it reads messages from the standard input, and then it will use the provided Network class to simulate sending the messages to the recipient. The Network class randomly shuffles the passes messages and then it passes them to the recipient using recipient.receive(const Message&) method. After all messages are delivered, the recipient uses its own method print_messages to print all the received messages to the standard output, and just before doing that, it uses its own fix_order method to fix the order of retrieved messages. For that purpose, it uses std::sort() algorithm to sort the std::vector of received messages and this is the reason your Message class implementation has to provide the < operator.
Input Format
The input is read by the provided locked code template. It contains several lines of text messages in the order that they will be sent over the network.
Constraints
There will be at most 10 lines in the input.
Each line will contain at most 20 characters
Output Format
The output should be produced by the provided locked code template and it is produced as described in details in the statement. The expected order of printed messages is the same as the one in the input.
Solution :
Solution in C :
class Message {
public:
Message() {}
Message(const string& text, int id) : text_(text), id_(id) {}
const string& get_text() {
return text_;
}
bool operator<(const Message& rhs) const {
return this->id_ < rhs.id_;
}
private:
string text_;
int id_;
};
class MessageFactory {
public:
MessageFactory() {}
Message create_message(const string& text) {
return Message(text, current_id++);
}
private:
int current_id = 0;
};
View More Similar Problems
Inserting a Node Into a Sorted Doubly Linked List
Given a reference to the head of a doubly-linked list and an integer ,data , create a new DoublyLinkedListNode object having data value data and insert it at the proper location to maintain the sort. Example head refers to the list 1 <-> 2 <-> 4 - > NULL. data = 3 Return a reference to the new list: 1 <-> 2 <-> 4 - > NULL , Function Description Complete the sortedInsert function
View Solution →Reverse a doubly linked list
This challenge is part of a tutorial track by MyCodeSchool Given the pointer to the head node of a doubly linked list, reverse the order of the nodes in place. That is, change the next and prev pointers of the nodes so that the direction of the list is reversed. Return a reference to the head node of the reversed list. Note: The head node might be NULL to indicate that the list is empty.
View Solution →Tree: Preorder Traversal
Complete the preorder function in the editor below, which has 1 parameter: a pointer to the root of a binary tree. It must print the values in the tree's preorder traversal as a single line of space-separated values. Input Format Our test code passes the root node of a binary tree to the preOrder function. Constraints 1 <= Nodes in the tree <= 500 Output Format Print the tree's
View Solution →Tree: Postorder Traversal
Complete the postorder function in the editor below. It received 1 parameter: a pointer to the root of a binary tree. It must print the values in the tree's postorder traversal as a single line of space-separated values. Input Format Our test code passes the root node of a binary tree to the postorder function. Constraints 1 <= Nodes in the tree <= 500 Output Format Print the
View Solution →Tree: Inorder Traversal
In this challenge, you are required to implement inorder traversal of a tree. Complete the inorder function in your editor below, which has 1 parameter: a pointer to the root of a binary tree. It must print the values in the tree's inorder traversal as a single line of space-separated values. Input Format Our hidden tester code passes the root node of a binary tree to your $inOrder* func
View Solution →Tree: Height of a Binary Tree
The height of a binary tree is the number of edges between the tree's root and its furthest leaf. For example, the following binary tree is of height : image Function Description Complete the getHeight or height function in the editor. It must return the height of a binary tree as an integer. getHeight or height has the following parameter(s): root: a reference to the root of a binary
View Solution →