104 lines
4.2 KiB
C++
104 lines
4.2 KiB
C++
// Adaptation to the code found at
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// Week 5: Lectures
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// Demonstrates sorted linked list
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#include <iostream>
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using namespace std;
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/////////////////////////////////////////////////////////////
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class Node {
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public:
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int filenumber; // the file number
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Node *pNext; // ptr to next link in list
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//----------------------------------------------------------
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Node(int value) : // constructor
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filenumber(value), pNext(NULL) {}
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//----------------------------------------------------------
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void displayNode() // display ourselves {22}
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{
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cout << "{" << filenumber << "} ";
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}
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//----------------------------------------------------------
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}; // end class Node
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/////////////////////////////////////////////////////////////
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class NodeList {
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private:
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Node *pFirst; // ptr to first link on list
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public:
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//----------------------------------------------------------
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NodeList() : pFirst(NULL) // constructor
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{} // no links on list yet
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//----------------------------------------------------------
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~NodeList(){ // destructor
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while(!isEmpty()){ // until it's empty,
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removeFirst(); // remove it
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}
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}
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//----------------------------------------------------------
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bool isEmpty() // true if list is empty
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{ return pFirst == NULL; }
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//----------------------------------------------------------
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Node *getFirst() // return first link
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{ return pFirst; }
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//----------------------------------------------------------
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void insert(int value) // insert, in order
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{
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Node* pNewLink = new Node(value); // make new link
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Node* pPrevious = NULL; // pointer to previous
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Node* pCurrent = pFirst; // start at first
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// Look for position prior to the end of the list
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// We quicksort insert by value
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while(pCurrent != NULL && value > pCurrent->filenumber)
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{
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pPrevious = pCurrent; // adjust previous ptr
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pCurrent = pCurrent->pNext; // go to next item
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}
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// Insert link the link
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if(pPrevious==NULL) // at beginning of list
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pFirst = pNewLink; // first --> newLink
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else // not at beginning
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pPrevious->pNext = pNewLink; // old prev --> newLink
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pNewLink->pNext = pCurrent; // newLink --> old current
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} // end insert()
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//----------------------------------------------------------
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void removeFirst() // delete first link
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{ // (assumes list not empty)
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Node *pTemp = pFirst; // save first
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pFirst = pFirst->pNext; // unlink it: first-->old next
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delete pTemp; // delete old first
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}
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//----------------------------------------------------------
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void displayList() {
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cout << "List (value): ";
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Node *pCurrent = pFirst; // start at beginning of list
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while (pCurrent != NULL) // until end of list,
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{
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pCurrent->displayNode(); // print data
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pCurrent = pCurrent->pNext; // move to next link
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}
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cout << endl;
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}
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//----------------------------------------------------------
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}; // end class NodeList
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/////////////////////////////////////////////////////////////
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int main() {
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NodeList theList; // make new list
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cout << "Demonstrating the sorted link-list program" << endl;
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theList.insert(421003);
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theList.insert(100298);
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theList.insert(494002);
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theList.insert(93);
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theList.insert(3994);
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theList.insert(21093);
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theList.insert(3949500);
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theList.insert(29100);
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theList.insert(6493939);
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theList.insert(202814);
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theList.insert(506984);
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theList.insert(2);
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theList.insert(665778);
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cout << " This is all the values that are now in the linked list" << endl;
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theList.displayList();
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return 0;
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} |