Intro to data structures and algorithms
LinearSearch(numbers, numbersSize, key) { i = 0 while (i < numbersSize) { if (numbers[i] == key) return i i = i + 1 } return -1 // not found } Numbers: 54, 79, 26, 91, 29, 33 Which is Best, Worst, or neither Key = 26 Key= 54 Key = 82
26 is neither best nor worst 54 is best 82 is worst
FindMax(inputArray) { max = inputArray[0] for (i = 1; i < inputArray.size; ++i) { if (inputArray[i] > max) { max = inputArray[i] } } return max } What will return from this array of integers? 13, 7, 45,-3,92,17
92 because it's the max number
Using that same code from question 18: To adapt the algorithm to display the top 10 salesperson, what modifications are required? A) only the array creation B) all loops in the algorithm C) Both the creation and loops
A only the array creation
The _____ ADT is the better match for the program's requirements. A) queue B) list C) A and B
B list
DisplayTopFiveSalespersons(allSalespersons) { topSales = Create array with 5 elements // Initialize all array elements with a negative sales total for (i = 0; i < topSales⇢length; ++i) { topSales[i]⇢name = "" topSales[i]⇢salesTotal = -1 } for each salesPerson in allSalespersons { if (salesPerson⇢salesTotal > topSales[topSales⇢length - 1]⇢salesTotal) { topSales[topSales⇢length - 1]⇢name = salesPerson⇢name topSales[topSales⇢length - 1]⇢salesTotal = salesPerson⇢salesTotal SortDescending(topSales) } } // Display the top five salespersons for (i = 0; i < topSales⇢length; ++i) { Display topSales[i] } } Which of the following is not equal to the number of items in the topSales array? A) topSales--->length B) 5 C) allSalesperson--->length
C allSalesperson--->length
The list ADT _____. A) Can be implemented using an array B) Can be implemented using a linked list C) Can be implemented in numerous ways
C can be implemented in numerous ways
A linked list stores items in an unspecified order. True or False
False
A list ADT's underlying data structure has no impact on the program's execution. True or False
False
A programmer must know the underlying implementation of the list ADT in order to use a list. True or False
False
ADTs are only supported in standard libraries. True or False
False
An algorithm's best and worst case scenarios are always different. True or False
False
An efficient algorithm exists for all computational problems. True or False
False
Runtime and memory usage are the only two resources making up computational complexity. True or False
False
The linear search algorithm's best case scenario is when N = 0. True or False
False
The underlying data structure for a list data structure is the same for all programming languages. True or False
False
Two different algorithms that produce the same result have the same computational complexity. True or False
False
What are the most common resources considered?
Runtime and Memory Usage
A list node's data can store a record with multiple subitems. True or False
True
A node in binary tree can have zero, one, or two children. True or False
True
An algorithm with a polynomial runtime is considered efficient. True or False
True
An efficient algorithm to solve an NP-complete problem may exist True or False
True
Computational complexity analysis allows the efficiency of algorithms to be compared. True or False
True
Items stored in an array can be accessed using a positional index. True or False
True
Knowledge of an ADT's underlying implementation is needed to analyze the runtime efficiency. True or False
True
Python, C++, and Java all provide built-in support for a deque ADT. True or False
True
Use code on question 18: If allSalespersons only contains three elements, the DisplayTopFiveSalespersons algorithm will display elements with no name and negative sales. True or False
True
NP-complete
are a set of problems for which no known efficient algorithm exists.
algorithm
describes a sequence of steps to solve a computational problem or perform a calculation
Binary tree
is a data structure in which each node stores data and has up to two children, known as a left child and a right child.
Linked List
is a data structure that stores an ordered list of items in nodes, where each node stores data and has a pointer to the next node.
Array
is a data structure that stores an ordered list of items, where each item is directly accessible by a positional index.
Hash Table
is a data structure that stores unordered items by mapping (or hashing) each item to a location in an array.
abstract data type (ADT)
is a data type described by predefined user operations, such as "insert data at rear," without indicating how each operation is implemented.
space complexity
is a function, S(N), that represents the number of fixed-size memory units used by the algorithm for an input of size N.
runtime complexity
is a function, T(N), that represents the number of constant time operations performed by the algorithm on an input of size N.
Data Structure
is a way of organizing, storing, and performing operations on data.
Set
is an ADT for a collection of distinct items.
Dynamic Array
is an ADT for holding ordered data and allowing indexed access.
List
is an ADT for holding ordered data.
Queue
is an ADT in which items are inserted at the end of the queue and removed from the front of the queue.
Stack
is an ADT in which items are only inserted on or removed from the top of a stack.
Computational complexity
is the amount of resources used by the algorithm.
Record
is the data structure that stores subitems, often called fields, with a name associated with each subitem.
worst case
is the scenario where the algorithm does the maximum possible number of operations.
best case
is the scenario where the algorithm does the minimum possible number of operations
auxiliary space complexity
is the space complexity not including the input data.
Algorithm efficiency
is typically measured by the algorithm's computational complexity.
Bag
s an ADT for storing items in which the order does not matter and duplicate items are allowed.
computational problem
specifies an input, a question about the input that can be answered using a computer, and the desired output.
