Data Structure and Algorithms

The slides that follow present a basic introduction to C - structures that we will need in order to understand fundamental data structures. • Arrays allow us to define types of variables that can hold several data items of the same kind. • In contrast, structure is an example of user defined data type available in C that allows us to combine data items of different kinds. • Structures are used to represent a record. Suppose we want to keep track of our books in a library. We might wa...

A list of finite number of homogenous data elements • Data elements could be § Characters § Numbers § Structures Note!: After compilation, elements of array are stored in successive memory location Exception: User defined higher dimensional arrays

// // main.c // Testing Filter // // Copyright © 2016 James Okello. All rights reserved. #include <stdio.h> #include "test_c_filter.h" int main(int argc, const char * argv[]) { // insert variables & code here... printf("Hello, World!n"); test_filter_parameters(); // prototype of this function in header file return 0; // return a value if necessary

Given some vector v, it possible to create a number (or a set) of vectors that when linearly combined will give any vector of a type similar to v § Similarly, given a graph, it is possible to create sub- graphs that together they define the original graph ü Note that a graph is constituted of vertices and edges

Given • a matrix variable “matrixA” of type double and size N-by-M (N rows and M columns) • a vector variable “vectorB” of type double and size M-by-1 Assume the variables vectorB, vectorC and matrixA have been declared #define SIZE_N 20 #define SIZE_M 10 : double matrixA[SIZE_N][SIZE_M], vectorB[SIZE_M], vectorC[SIZE_N];

A non-linear DS used to represent data containing a hierarchical relationship between elements - A set of nodes storing elements in a parent-child relationship - A data structure which consists of a finite set of elements called nodes or vertices a finite set of directed arcs which connect the nodes

Input: Zero or more quantities are externally supplied • Output: At least one quantity is produced • Definiteness: Instructions has to be clear & unambiguous • Finiteness: Algorithm must always terminate after a finite set of instructions

Data structure is a collection of data items in memory There is a corresponding number of operations provided to manipulate data structures Data may be organized in many different ways- the logical or mathematical model organization of data is also referred to as data structure • Data refers to a value or a set of values These values may represent some observation from experiment, marks obtained by a student in an examination, age (i.e. 22), e.t.c.

The study of data structures includes: • Logical description of the data structure • Implementation of the data structure • Quantitative analysis of the data structure Includes determining: - Amount of memory needed to store the data structure - Time required to process

Consider const int result = 10; Trying to change value of result by assigning result to a different value WRONG: result += 30;