C++ programming coding

// Mutlu Mete // Bag implementation using linked list, A dynamic data container // CSCI 520 // #include <iostream> #include <stdio.h> #include <string> #include <stdlib.h> using namespace std; // A struct to keep items struct item { string data; item *next; item(string x, item* t) { // constructor data = x; next = t; } }; typedef item * link; // A class to represent Bag, which can hold and strings in an linked list // The items (strings) are not sorted in the list. class Bag { public: Bag(); // Construction bool add (string str); // Adds a new item to bag bool has (string str); // Check if Bag has this item bool remove (string str); // Delete the str from the bag unsigned short getCapacity (); // get the capacity of the Bag. Is there any capacity void ListBag(); // List all items of Bag. unsigned short getSize(); // How many items the Bag has private: link first; // A pointer to show the first node link last; // A pointer to show the last node unsigned short size; // how many items Bag has }; Bag::Bag() // Initialize an instance of the class { size = 0; first = last = NULL; // At the beginning both, first and last are null cout << "A new bag with " << getCapacity() << " was created...!" << endl ; } bool Bag::add(string str) { link AddItem = new item(str,NULL); // dynamically create a new struct/item if ( AddItem == NULL) return false; // not enought memory if ( first == NULL ) first = AddItem; // first item to be added else last->next = AddItem; // add to the end of array last = AddItem; size++; return true; // Yeah, added. } bool Bag::remove(string str) // Delete the str from the bag { link back; link front; if (first == NULL) return false; back=front=first; if(front->data == str) // delete this { if (first == last) // there is only one item, which will be deleted first = last = NULL; else first = first ->next; // first of many items is being deleted delete front; size--; return true; } front = front->next; // if reach this line, the first item of bag is not being deleted. while (front != NULL) { if (front->data == str) { back->next = front->next; // a mid-item is being deleted. By-pass the (front) if (front == last) last = back; // the last item is being deleted delete front; size--; return true; } back = front ; front = front -> next; } return false; // if reach this line, item is not found in the list. } void Bag::ListBag() // List, print out, all items in the arrays, // make 5 coloumns { cout << size << ": " ; link it = first; // it means iterator, visit all items one by one. int i=0; // i is used to format the outpur while (it != NULL) { cout << it->data << " "; it = it->next; if ( (i+1)%5 == 0) cout << endl; i++; } cout << endl; } // How many items the Bag has unsigned short Bag::getSize () { return size; } bool Bag::has(string str) // Check if the bag has item "str", // You can return bool too { link it = first; for (int i=0; i < size; i++) { if (it->data == str) return true; it = it->next; } return false; } unsigned short Bag::getCapacity () { return 10000; // A made-up number. } int main(int argc, const char * argv[]) { Bag bigBag; string tempStr; char sel = ' '; while (sel != 'e') { cout << "(i)nsert, (d)elete, (s)earch, (e)xit: "; cin >> sel; switch(sel) { case 'i': cout << "\nString to be inserted:"; cin >> tempStr; bigBag.add (tempStr); bigBag.ListBag(); break; case 'd': cout << "\nString to be deleted: "; cin >> tempStr; bigBag.remove(tempStr); bigBag.ListBag(); break; case 's': cout << "\nString to be searched: "; cin >> tempStr; cout << bigBag.has(tempStr) << endl; break; default: break; } } }