The Bucharest University of Economic Studies. Data Structures. Associate Professor Mihai DOINEA

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1 The Bucharest University of Economic Studies Data Structures Associate Professor Mihai DOINEA

2 Assessment Final exam: 60% Short quiz: 10% Practical test: 50% Laboratory grading: 40% Ongoing evaluation: 20% Practical evaluation: 20% Website:

3 Content Fundamentals 1. Pointers a. Stack vs. Heap b. Parameters passing 2. Bits structures 3. Memory classes 4. Union structure

4 Content Linear structures 1. Dynamic data structures Linked and double linked lists 2. Stack and Queue 3. Hash Table array of lists 4. Heap complete trees, array implementation 5. Collections Maps & Sets

5 Content Nonlinear structures 1. Binary Search Trees 2. Binary Balanced Trees vs. Imbalanced Trees 3. B trees 4. Graphs

6 Content Applications 1. Compression 2. String processing 3. Sorting 4. Conversions 5. Library functions

7 Data Structures

8 Data Structures

9 Data Structures Instrument for data usage which helps to create information; A method of organizing and storing units of data in the external and internal memory; A collection of variables stored in a predefined state in memory;

10 Data Structures Relationship among data elements that dictates how data is recorded, manipulated, stored and presented.

11 Necessity Complexity Input data Processing depth Algorithm efficiency Resource consumption Memory usage Execution time

12 Big-O Analysis 1 C N log N N C? N N 2 N log N

13 Big-O Analysis

14 Memory Structure Data - DS Stack - SS Code - CS

15 Memory Intel 8086 Registers Segment registers: Code segment: CS Data segment: DS Stack segment: SS

16 Stack

17 Function comparisons C/C++ Source #include<stdio.h> void main() { static char a = 7; static char b = 9; static int c = 0; c = a+b; } MicroProcesor BUS RAM Assembly Language.model small.stack 16.data a db 7 b db 9 c dw 0.code start: mov mov DS, AX mov AL,a add AL,b mov c,ax mov AX, 4C00h int 21h end start Machine code B E D8 A A B8 00 4C CD

18 Pointers Variables which have values the address of a memory area; The address size is given by the processor architecture;

19 Pointers Pointer variable utility Source code optimization / memory allocation Returning values as result of a function call Implementing arrays of characters

20 Pointers Definition: tip *nameptr; Initialization: nameptr = &namevar; Usage: tip namevar = *nameptr;

21 Pointers Example int *ip; // integer pointer double **dp; // pointer to pointer to double float *vfp[10]; // array of 10 pointers to float char *ch; // pointer to a char int (*suma)(lista_param); //pointer to a function

22 Pointers Values Pointer s values tip *p1; tip *p1=null; tip *p1=&a; 0xcccccccch 0x h 0x00ABF23Ch

23 Pointers Applications Functions parameter passing Call by value Call by address Reference (&) Pointers (*)

24 Pointers Operators for a pointer of type T* pt, operators --/++ add or subtract the address of the pointer with sizeof(t) bytes; for a pointer of type T* pt, expression pt + k or pt k adds or subtracts a number of k * sizeof(t) bytes, where k is an integer value; the difference between two pointers within the same range of values is the number of elements between the two addresses; the sum between 2 pointers is not allowed;

25 Pointers Frequent errors Wrong addressing Memory leak Uninitialized Errors Dangling pointers

26 Pointers const modifier i n t v a r 1 = 7 ; i n t v a r 2 = 8 ; // constant pointer to integer i n t * c o n s t p tr = & v a r 1 ; p t r = & v a r 2 ; i n s t e a d * p t r = v a r 2 ; // pointer to constant integer i n t c o n s t * p i n t; // c o n s t i n t * p i n t ; p i n t = & v a r 1 ; * p i n t = 4 ; // constant pointer to constant integer c o n s t i n t * c o n s t p i n t 2 = &var;

27 Function pointers syntax: Declaring: returned_type (* pointer_name) (args_list); Initializing: pointer_name = function_name; Invoking: pointer_name (args_list);

28 Function pointers: int add(int a, int b) { return a+b; } int product(int a, int b) { return a*b; Declaration: int (*functie)(int, int); Initializition: functie = add; functie = product; Function pointer call: functie(5,7); }

29 Resources Ion IVAN, Marius POPA, Paul POCATILU Structuri de date, Editura ASE, Bucuresti, 2008, ISBN Ion SMEUREANU Programarea in limbajul C/C++, Editura CISON, 2001 Michael MAIN Data Structures & Other Objects Using Java, Editura Pearson, 2012, ISBN:

The Bucharest University of Economic Studies. Data Structures. Heap Priority Queues Maps and Sets

The Bucharest University of Economic Studies Data Structures Heap Priority Queues Maps and Sets Heap A heap is a specialized tree-based data structure that satisfies the property: if A is parent for B