90 lines
3.4 KiB
C++
90 lines
3.4 KiB
C++
#ifndef SINGLY_LINKED_LIST_H
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#define SINGLY_LINKED_LIST_H
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#include <cassert>
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#include "sequence.h"
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namespace seq
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{
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class SinglyLinkedListNode
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{
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public:
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// return a reference to the stored item
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int& get_item() { return this->item; }
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// return pointer to next node, or nullptr if this is the final node
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SinglyLinkedListNode* get_next() const { return this->next; }
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// overwrite the item stored in this node
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void set_item(int in_item) { this->item = in_item; }
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private:
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int item = 0;
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SinglyLinkedListNode* next = nullptr;
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// attach a node to this node
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// if there was a node attached to this previously, it is NOT deleted!
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void set_next(SinglyLinkedListNode* in_next) { this->next = in_next; }
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friend class SinglyLinkedList; // allow SinglyLinkedList to access private members
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};
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class SinglyLinkedList: public Sequence
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{
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public:
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bool empty() const { return (this->head == nullptr); } // test whether the singly linked list is empty
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size_t size() const; // return the size (number of items in the singly linked list)
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// it is the caller's responsibility to ensure that the list is not empty when calling front() or back()!
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int& front() { assert(this->head); return this->head->get_item(); } // return a reference to the first item
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int& back() { assert(this->tail); return this->tail->get_item(); } // return a reference to the final item
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// return a reference to the item at position i of the list, counting from 0
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// it is the caller's responsibility that the index is within range
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int& at(int i) { return this->index(i)->get_item(); }
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// return pointer to the head/tail node
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SinglyLinkedListNode* begin() const { return this->head; }
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SinglyLinkedListNode* end() const { return this->tail; }
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// return pointer to the node at position i, counting from 0
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SinglyLinkedListNode* index(int i) const;
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/*
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* accepts an additional item into the singly linked list;
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* by default, this is done at the back end of the list
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* call push_front(...) to push an element at the front
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*
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* the list takes ownership of the copy (but not of the original!)
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*/
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void push(const int& pushed_item) { this->push_back(pushed_item); }
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void push_back(const int& pushed_item);
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void push_front(const int& pushed_item);
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/*
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* removes an item from the list (front end by default)
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* to do the same at the back, call pop_back()
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*/
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void pop() { this->pop_front(); }
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void pop_front();
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void pop_back();
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void clear() { while(!this->empty()) this->pop(); } // remove all the items from the list
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// it is the caller's responsibility that the index is within range
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void insert_at(int i, const int& inserted_item); // insert an item at index i
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void erase_at(int i); // remove the item at index i
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// it is the caller's responsibility that the node is actually part of the list
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void insert_successor_to(SinglyLinkedListNode* predecessor, const int& inserted_item); // insert an item after given node
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void erase_successor_to(SinglyLinkedListNode* predecessor); // remove the item after given node
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~SinglyLinkedList() { this->clear(); }
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private:
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SinglyLinkedListNode* head = nullptr;
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SinglyLinkedListNode* tail = nullptr;
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};
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}
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#endif
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