Data Structures and Algorithms – C++ Implementation ppt

Data Structures and Algorithms – C++ Implementation Ho Chi Minh City University of Technology Faculty of Computer Science and Engineering BK TP.HCM BK TP.HCM Huỳnh Tấn Đạt Email: htdat@cse.hcmut.edu.vn Home Page: http://www.cse.hcmut.edu.vn/~htdat/ Pointer in C++  Declaration Node *ptr;  Create an object ptr = new Node();  A pointer usage printf (“Data in node: %d”, ptr - >data); ptr ptr ??? Slide 2Faculty of Computer Science and Engineering – HCMUT printf (“Data in node: %d”, ptr - >data);  Destroy an object delete ptr;  NULL pointer ptr = NULL; ptr ??? ptr Pointer in C++  Be careful in these cases: ptr1 ptr2 Before ptr1 = ptr2; Before delete ptr1; ptr1 = NULL; ptr1 ptr2 Slide 3Faculty of Computer Science and Engineering – HCMUT After ptr1 = ptr2; ptr1 ptr2 After delete ptr1; ptr1 = NULL; ptr1 ptr2 Garbage Dangling reference problem Parameter Passing Techniques void func(int* a, int* b){ int *t; t = a; a = b; b = t; } void main() { int *p1 = new int; *p1 = 10; int *p2 = new int; *p2 = 20; func(p1, p2); printf (“%d”, * p1); Slide 4Faculty of Computer Science and Engineering – HCMUT } void func(int* &a, int* &b){ int *t; t = a; a = b; b = t; } printf (“%d”, * p1); printf(“%d”, *p2); } Parameter Passing Techniques void func(int* &a, int* b){ int *t; t = a; a = b; b = t; } void main() { int *p1 = new int; *p1 = 10; int *p2 = new int; *p2 = 20; func(p1, p2); printf (“%d”, *p1); Slide 5Faculty of Computer Science and Engineering – HCMUT } void func(int* a, int* &b){ int *t; t = a; a = b; b = t; } printf (“%d”, *p1); printf(“%d”, *p2); } Parameter Passing Techniques void func(int **a, int **b){ int *t; t = *a; *a = *b; *b = t; } void main() { int *p1 = new int; *p1 = 10; int *p2 = new int; *p2 = 20; func(&p1, &p2); printf (“%d”, *p1); Slide 6Faculty of Computer Science and Engineering – HCMUT } printf (“%d”, *p1); printf(“%d”, *p2); } Linked Lists  A linked list is an ordered collection of data in which each element contains the location of the next element Element = Data + Link head data link Slide 7Faculty of Computer Science and Engineering – HCMUT empty linked list Nodes number name A node with one data field number A node with three data fields id Slide 8Faculty of Computer Science and Engineering – HCMUT name numberid A node with one structured data field Nodes Linked List Structure count head list count <integer> Data node structure data link node data < dataType > dataType key <keyType> Slide 9Faculty of Computer Science and Engineering – HCMUT count <integer> head <pointer> end endend end list data < dataType > link <pointer> end endend end node key <keyType> field1 <…> field2 <…> … fieldN <…> end endend end dataType Nodes – Implementation in C++ struct Node { int data; Node *next; }; node data <dataType> link <pointer> end node Slide 10Faculty of Computer Science and Engineering – HCMUT [...]... ItemType data; Node *next; }; Faculty of Computer Science and Engineering – HCMUT Slide 12 Nodes – Implementation in C++ Node *p = new Node(); p- >data = 5; coutdata; Node *q = p; coutdata; Node *r = new Node(); r- >data = 10; q->next = r; coutnext- >data; Faculty of Computer Science and Engineering – HCMUT p 5 q r 10 Slide 13 Nodes – Implementation in C++. ..Nodes – Implementation in C++ Node *p = new Node(); p- >data = 5; coutdata; Node *q = p; coutdata; Node *r = new Node(); r- >data = 10; q->next = r; coutnext- >data; Faculty of Computer Science and Engineering – HCMUT p 5 q r 10 Slide 11 Nodes – Implementation in C++ struct Node { int data; Node *next; }; struct Node { float data; Node *next; }; template data this->next } ItemType> = NULL; data) { = data; = NULL; ItemType data; Node *next; }; Faculty of Computer Science and Engineering – HCMUT Slide 14 Linked List – Implementation in C++ template class LinkedList{ public: LinkedList(); ~LinkedList(); protected: Node* head; int count; }; Faculty of Computer Science and Engineering – HCMUT list... data from a linked list and returns it to calling module Pre list is metadata structure to a valid list pPre is a pointer to predecessor node pLoc is a pointer to node to be deleted dataOut is variable to receive deleted data Post data have been deleted and returned to caller Faculty of Computer Science and Engineering – HCMUT Slide 35 Delete Node Algorithm 1 dataOut = pLoc -> data 2 if (pPre = null)... list Pre list is metadata structure to a valid list pPre is pointer data s logical predecessor dataIn contains data to be inserted Post data have been inserted in sequence Return true if successful, false if memory overflow Faculty of Computer Science and Engineering – HCMUT Slide 29 Insert Node Algorithm 1 allocate(pNew) 2 if (memory overflow) 1 return false 3 pNew -> data = dataIn 4 if (pPre = null)... head Faculty of Computer Science and Engineering – HCMUT Slide 21 Create List Algorithm createList (ref list ) Initializes metadata for a linked list Pre list is a metadata structure passed by reference Post metadata initialized 1 list.head = null 2 list.count = 0 3 return End createList Faculty of Computer Science and Engineering – HCMUT Slide 22 Linked List Implementation template link = pLoc -> link recycle (pLoc) 39 2 count recycled pPre After pLoc 75 head list Faculty of Computer Science and Engineering – HCMUT Slide 34 Delete Node Algorithm Algorithm deleteNode (ref list , val pPre , val pLoc ref dataOut ) Delete data. .. Science and Engineering – HCMUT 52 Slide 27 Insert at End Before 3 count head 39 52 list pPre pNew -> link = pPre -> link pPre -> link = pNew After 4 count 75 list head 39 pPre Faculty of Computer Science and Engineering – HCMUT pNew 52 134 75 pNew 134 Slide 28 Insert Node Algorithm Algorithm insertNode (ref list , val pPre , val dataIn ) Inserts data into a new node... Science and Engineering – HCMUT Slide 23 Insert Node Allocate memory for the new node and set up data Point the new node to its successor Point the new node's predecessor to it Faculty of Computer Science and Engineering – HCMUT Slide 24 Insert into Empty List Before 0 count 75 head list pNew pNew -> link = list head list.head = pNew After 1 count head 75 list pNew Faculty of Computer Science and Engineering... DeleteLast(); int DeleteItem(int Postion); int GetItem(int Position, List_ItemType &dataOut); void Print2Console(); void Clear(); // Augment your methods for linked list here!!! LinkedList* Clone(); protected: // Faculty of Computer Science and Engineering – HCMUT Slide 18 Linked List Implementation How to use Linked List data structure? int main(int argc, char* argv[]) { LinkedList* myList . Data Structures and Algorithms – C++ Implementation Ho Chi Minh City University of Technology Faculty of Computer Science and Engineering BK TP.HCM BK TP.HCM Huỳnh. Science and Engineering – HCMUT Nodes – Implementation in C++ Node *p = new Node(); p-> ;data = 5; cout<< p-> ;data; Node *q = p; cout<< q-> ;data; Node