CIS 205 Intro to Programming C++ Chapter 7-Arrays & Vectors & Chapter 8-Searching and Sorting Arrays

If you want to use a vector you must

#include<vector>

(2)The size of an array is:

(number of elements) * (number of bytes for each element)

size

(number of elements)*(size of each element)

tests [i]++

// add 1 to tests[i]

tests[i++]

// increment i, no effect on tests

In the definition: int tests [5]; What is 5?

5 is the size declarator

Set first to 0 Set last to the last subscript in the array Set found to false Set position to -1 While found is not true and first is less than or equal to last Set middle to the subscript half-way between array[first] and array[last]. If array[middle] equals the desired value Set found to true Set position to middle Else If array[middle] is greater than the desired value Set last to middle - 1 Else Set first to middle + 1 End If. End While. Return position.

Algorithm for binary search

set found to false; set position to -1; set index to 0 while index < number of elts. and found is false if list[index] is equal to search value found = true position = index end if add 1 to index end while return position

Algorithm of a Linear Search

must also be reflected in the prototype,header.

Array Size

Which is the second benefit of a linear search?

Array can be in any order

Requires array elements to be in order

Binary Search

When using this search, the algorithm starts with the middle element of the array. From there, it searches the first half on one side of the middle element, and then moves onto the other searching for the correct value. The search repeats this process until it produces the correct value or there are no more elements to examine.

Binary Search

Concept of bubble sort

Compare the first two elements of an array. If out of order, exchange them and put them into order. Move to next element, and repeat the process, and exchange when necessary. Continue until the end of the array. Pass through the array again, exchanging values when necessary, and repeat until passes are made with no exchanges.

Which is the first benefit of a linear search?

Easy algorithm to understand

An Array, numlist contains the numbers 1,5,18,2,23,68,4. If prompted to search for the value 2, this type of search examines 1,5,18, and 2.

Example of Linear Search

What is the disadvantage of using a linear search?

Inefficient and slow

This type of search is also called sequential search

Linear

Starting at the first element, this algorithm sequentially steps through an array examining each element until it locates the value it is searching for

Linear Search

Two Algorithms discussed in the chapter are:

Linear and Binary

____ occurs when you use array subscripts that are off by one.

Off-by-one error

two or more arrays that contain related data

Parallel arrays

size declarator

Shows the number of elements in the array

can define one array for multiple sets of data

Two-Dimensional Arrays

is like a table in a spreadsheet

Two-Dimensional Arrays

uses two size declarators in definition

Two-Dimensional Arrays

How are arrays declared?

Using [ ] operator

types of sort

alphabetical, ascending numeric, descending numeric

You can define arrays with

any number of dimensions.

Values

are stored in adjacent memory locations

Sort

arranges values into an order

____ can be used as regular variables

array elements

Array numlist2 contains 2,3,5,11,17,23,29. If you search for the value 11, what happens in the first iteration of the search?

binary search examines 11, and stops, since it is the middle element of the array.

Array numlist2 contains 2,3,5,11,17,23,29. If you search for the value 7, what happens in the search?

binary search examines 11,3,5, and stops since the value is not in the middle element or the lower side of the element.

two sorting algorithms

bubble sort and selection sort

Array names in functions are like reference variables;

changes made to array in a function are reflected in actual array in calling function

you can display the contents of a ____ by sending its name to cout

character array

To remove all contents of vector, use ____ member function:

clear

In a two dimensional array, the Second declarator is number of____.

columns

Array numlist3 finished the second pass of bubble sort. It originally displayed 17,23,5, and 11. After first pass it displays 17,5,11, and 23. After second pass it displays 5,11,17, and 23. What happens in the third pass of bubble sort?

compare 5 and 11; in order, do not exchange. compare 11 and 17; in order, do not exchange. compare 17 and 23; in order, do not exchange. The array is in order.

Array numlist3 contains 17,23,5, and 11. What happens in the first pass of bubble sort?

compare values 17 and 23; they're in order, so no exchange. compare values 23 and 5; not in order, so they get exchanged. compare values 23 and 11; not in order, exchange them. The array now displays 17,5,11,23.

Array numlist3 finished the first pass of bubble sort. It originally displayed 17,23, 5, and 11. It now displays 17,5,11,23. What happens in the second pass of bubble sort?

compare values 17 and 5; not in order, exchange them. compare values 17 and 11; not in order, exchange them. Finally, compare 17 and 23; in correct order, there is no exchange.

You can access element with

constant or literal subscript

use a ____ to keep track of the number of items stored in the array.

counter variable

benefits of bubble sort-

easy to understand and implement

to compare two arrays, you must compare ____.

element by element

Second of three array sections when using binary search

elements on one side of the middle element

Third of three array sections when using binary search

elements on the other side of the middle element

To determine if vector is empty, use ____ member function:

empty

for (dataType rangeVariable : array) statement;

general format of the range-based for loop

all elements initialized to 0 by default

global array

values are stored in the array

in the order in which they appear in the list

arrays must be accessed via

individual elements

arrays can be initialized with an

initialization list

In the definition: int tests [5]; What is the data type?

int

You can use ____ as subscript

integer expression

the range-based for loop

is a loop that iterates once for each element in an array.

the last element's subscript is n-1, where n

is the number of elements in the array

If using C++ 11, you can initialize a vector with a

list of values

all elements uninitialized by default

local array

Search

locate an item in a list of information

concept for selection sort in ascending order-

locate smallest element in array. exchange it with element in position 0. locate next smallest element in array. exchange it with element in position 1. continue until all elements are arranged in order

disadvantage of selection sort

may not be as easy as bubble sort to understand

First of three array sections when using binary search

middle element

benefit of selection sort

more efficient than bubble sort, since it uses fewer exchanges.

benefit(s) of using a binary search:

much more efficient than linear search.

the last elements subscript is

n-1

____ are commonly used as size declarators

named constants

array elements can be treated as

ordinary variables of the same type as the array

When passing an array to function, it is common to

pass array size so that function knows how many elements to process

Use ____ member function to remove last element from vector:

pop_back

use ____ member function to add element to a full array or to an array that had no defined size

push_back

In C++ 11 you can use the ____ to display an array's contents

range-based for loop

Disadvantage(s) of using a binary search:

requires that array elements be sorted

Two-dimensional arrays are initialized

row-by-row

In a two dimensional array, the First declarator is number of ____.

rows

use ____ member to determine size of a vector

size

disadvantage of bubble sort-

slow for large arrays

Each element in an array is assigned a unique ____.

subscript

____ start at 0.

subscripts

In the definition: int tests [5]; What is the name of the array?

tests

the initialization list cannot exceed

the array size

the range based for loop automatically knows

the number of elements in an array

You can determine array size by

the size of the initialization list

if array is initialized with fewer initial values than the size declarator, the remaining elements will be set

to 0

(1) The size of an array is:

total number of bytes allocated for it

to define a function that takes an array parameter, ____

use empty [] for array argument

How do you pass an array to a function?

use the array name

Array

variable that can store multiple values of the same type

A data type defined in the Standard Template Library

vector

automatically adds space as more is needed-no need to determine size at definition

vector

can hold values of any type

vector

declare a vector with initial size of 30

vector <int> scores (30);

declare a vector to hold int element

vector <int> scores;

declare a vector initialized to size and contents of another vector

vector<int> finals(scores);

declare a vector with initial size of 30 and all elements set to 0

vector<int> scores (30,0);

sorting and searching algorithms can be applied to ____ as well as arrays.

vectors