This presentation describes an approach to analysis of common recursion patterns in purely functional code. The goal is to recognize common patterns and provide the user with hints how to improve them using standard FP techniques (map, fold etc.). This presentation was given as part of the Advanced Functional Programming Seminar at Utrecht University.
This presentation describes an approach to analysis of common recursion patterns in purely functional code. The goal is to recognize common patterns and provide the user with hints how to improve them using standard FP techniques (map, fold etc.). This presentation was given as part of the Advanced Functional Programming Seminar at Utrecht University.
Data Structure Introduction
Data Structure Definition
Data Structure Types
Data Structure Characteristics
Need for Data Structure
Stack Definition
Stack Representation
Stack Operations
Stack Algorithm
Program for Stack in C++
Linked List Definition
Linked List Representation
Linked List Operations
Linked List Algorithm
Program for Linked List in C++
Linked List Defination
Linked List Representation
Linked List Operations
Linked List Algorithm
Program for Linked List in C++
In java , I want you to implement a Data Structure known as a Doubly.pdfaromalcom
In java , I want you to implement a Data Structure known as a Doubly-Ended-Queue. it is a
“fair” data structure in that it implements a FIFO (First In First Out ) behavior. As such, it is
often used to implement various wait lists in computer systems. For example, jobs waiting to use
the CPU, jobs waiting for a printer, jobs waiting to be placed into RAM for execution. In short,
whenever we want a fair strategy for waiting we use queues.
A DEQUE (Doubly-ended-queue) is a related data structure. Although similar to a Queue, it
differs in that it allows for insertions AND deletions from either end of the list (both the front
and the rear).
Your implementation MUST use a doubly-linked-list implementation. You may not use a static
array implementation.
Thus, a Deque is a List but it is one which only concerns itself with the first and last positions for
any insertion or deletion. The 6 operations supported are :
public void insertFront( int item ) - insert the given item (as a node) into the first position of the
Deque.
public void insertRear( int item ) - insert the given item (as a node) into the last position of the
Deque.
public int deleteFront( ) - delete and return the element stored in the first node of the Deque.
public int deletRear( ) – delete and return the element stored in the last node of the Deque.
public boolean isempty( ) - returns true if the Deque is currently empty or false if it is not.
public void printDeque( ) - print the integers from the list, one per line, from the first element
through to the last in order.
Classes
Your program must implement the following 3 classes. public class dequeDriver
This class will contain your program’s main method. It will need to declare a deque object and
process input as indicated below.
Your program should prompt the user for the path of an input file. It should open the file for
input and process it line by line. Each line of the input file will have one of the following forms.
PR
IF
IR
DF
DR
The meanings of each input is as follows:
PR - print the current contents of the deque from front to rear using the printDeque( ) method of
the deque object.
IF - insert the given int value into the front of the deque.
IR - insert the given int value into the rear of the deque.
DF - delete the front value from the deque.
DR – delete the rear element of the deque.
Below is an example input file that your program should be able to process.
PR
IF 4
IF 5
IF 6
IR 7
PR
DR
PR
DF
PR
The output for the input file shown above is :
EMPTY DEQUE
----- Front -----
6
5
4
7
----- Rear -----
----- Front -----
6
5
4
----- Rear -----
----- Front -----
5
4
----- Rear -----
public class dequeNode
This class will implement the linked nodes that will be used to implement the deque itself.
It should have the following protected data members.
protected dequeNode next; // next pointer to next node
protected dequeNode prev; // previous pointer to previous node
protected int val; // the integer value stored within the dequeNod.
Insert works in constant time for either end of a linked list. Remove works in constant time only. Seems best that head of the linked list be the front of the queue so that all removes will be from the front. Inserts will be at the end of the list
queue datastructure made easy and datastructure explained in java. visit http://technoexplore.blogspot.com and http://hotjobstuff.blogspot.com for some other important presentations.
Earliest Galaxies in the JADES Origins Field: Luminosity Function and Cosmic ...Sérgio Sacani
We characterize the earliest galaxy population in the JADES Origins Field (JOF), the deepest
imaging field observed with JWST. We make use of the ancillary Hubble optical images (5 filters
spanning 0.4−0.9µm) and novel JWST images with 14 filters spanning 0.8−5µm, including 7 mediumband filters, and reaching total exposure times of up to 46 hours per filter. We combine all our data
at > 2.3µm to construct an ultradeep image, reaching as deep as ≈ 31.4 AB mag in the stack and
30.3-31.0 AB mag (5σ, r = 0.1” circular aperture) in individual filters. We measure photometric
redshifts and use robust selection criteria to identify a sample of eight galaxy candidates at redshifts
z = 11.5 − 15. These objects show compact half-light radii of R1/2 ∼ 50 − 200pc, stellar masses of
M⋆ ∼ 107−108M⊙, and star-formation rates of SFR ∼ 0.1−1 M⊙ yr−1
. Our search finds no candidates
at 15 < z < 20, placing upper limits at these redshifts. We develop a forward modeling approach to
infer the properties of the evolving luminosity function without binning in redshift or luminosity that
marginalizes over the photometric redshift uncertainty of our candidate galaxies and incorporates the
impact of non-detections. We find a z = 12 luminosity function in good agreement with prior results,
and that the luminosity function normalization and UV luminosity density decline by a factor of ∼ 2.5
from z = 12 to z = 14. We discuss the possible implications of our results in the context of theoretical
models for evolution of the dark matter halo mass function.
This pdf is about the Schizophrenia.
For more details visit on YouTube; @SELF-EXPLANATORY;
https://www.youtube.com/channel/UCAiarMZDNhe1A3Rnpr_WkzA/videos
Thanks...!
THE IMPORTANCE OF MARTIAN ATMOSPHERE SAMPLE RETURN.Sérgio Sacani
The return of a sample of near-surface atmosphere from Mars would facilitate answers to several first-order science questions surrounding the formation and evolution of the planet. One of the important aspects of terrestrial planet formation in general is the role that primary atmospheres played in influencing the chemistry and structure of the planets and their antecedents. Studies of the martian atmosphere can be used to investigate the role of a primary atmosphere in its history. Atmosphere samples would also inform our understanding of the near-surface chemistry of the planet, and ultimately the prospects for life. High-precision isotopic analyses of constituent gases are needed to address these questions, requiring that the analyses are made on returned samples rather than in situ.
(May 29th, 2024) Advancements in Intravital Microscopy- Insights for Preclini...Scintica Instrumentation
Intravital microscopy (IVM) is a powerful tool utilized to study cellular behavior over time and space in vivo. Much of our understanding of cell biology has been accomplished using various in vitro and ex vivo methods; however, these studies do not necessarily reflect the natural dynamics of biological processes. Unlike traditional cell culture or fixed tissue imaging, IVM allows for the ultra-fast high-resolution imaging of cellular processes over time and space and were studied in its natural environment. Real-time visualization of biological processes in the context of an intact organism helps maintain physiological relevance and provide insights into the progression of disease, response to treatments or developmental processes.
In this webinar we give an overview of advanced applications of the IVM system in preclinical research. IVIM technology is a provider of all-in-one intravital microscopy systems and solutions optimized for in vivo imaging of live animal models at sub-micron resolution. The system’s unique features and user-friendly software enables researchers to probe fast dynamic biological processes such as immune cell tracking, cell-cell interaction as well as vascularization and tumor metastasis with exceptional detail. This webinar will also give an overview of IVM being utilized in drug development, offering a view into the intricate interaction between drugs/nanoparticles and tissues in vivo and allows for the evaluation of therapeutic intervention in a variety of tissues and organs. This interdisciplinary collaboration continues to drive the advancements of novel therapeutic strategies.
Richard's aventures in two entangled wonderlandsRichard Gill
Since the loophole-free Bell experiments of 2020 and the Nobel prizes in physics of 2022, critics of Bell's work have retreated to the fortress of super-determinism. Now, super-determinism is a derogatory word - it just means "determinism". Palmer, Hance and Hossenfelder argue that quantum mechanics and determinism are not incompatible, using a sophisticated mathematical construction based on a subtle thinning of allowed states and measurements in quantum mechanics, such that what is left appears to make Bell's argument fail, without altering the empirical predictions of quantum mechanics. I think however that it is a smoke screen, and the slogan "lost in math" comes to my mind. I will discuss some other recent disproofs of Bell's theorem using the language of causality based on causal graphs. Causal thinking is also central to law and justice. I will mention surprising connections to my work on serial killer nurse cases, in particular the Dutch case of Lucia de Berk and the current UK case of Lucy Letby.
Multi-source connectivity as the driver of solar wind variability in the heli...Sérgio Sacani
The ambient solar wind that flls the heliosphere originates from multiple
sources in the solar corona and is highly structured. It is often described
as high-speed, relatively homogeneous, plasma streams from coronal
holes and slow-speed, highly variable, streams whose source regions are
under debate. A key goal of ESA/NASA’s Solar Orbiter mission is to identify
solar wind sources and understand what drives the complexity seen in the
heliosphere. By combining magnetic feld modelling and spectroscopic
techniques with high-resolution observations and measurements, we show
that the solar wind variability detected in situ by Solar Orbiter in March
2022 is driven by spatio-temporal changes in the magnetic connectivity to
multiple sources in the solar atmosphere. The magnetic feld footpoints
connected to the spacecraft moved from the boundaries of a coronal hole
to one active region (12961) and then across to another region (12957). This
is refected in the in situ measurements, which show the transition from fast
to highly Alfvénic then to slow solar wind that is disrupted by the arrival of
a coronal mass ejection. Our results describe solar wind variability at 0.5 au
but are applicable to near-Earth observatories.
2. Data Structures and Algorithms in Java 2/21
Queues
Objectives
• Queues
• Priority Queues
• Queue interface in java.util
3. Data Structures and Algorithms in Java 3/21
What is a queue?
3
• A queue is a waiting line that grows by adding
elements to its end and shrinks by taking
elements from its front
• A queue is a structure in which both ends are
used:
– One for adding new elements
– One for removing them
• A queue is an FIFO structure: First In/First Out
4. Data Structures and Algorithms in Java 4/21
Operations on a queue
4
• The following operations are needed to properly manage a
queue:
– clear() — Clear the queue
– isEmpty() — Check to see if the queue is empty
– enqueue(el) — Put the element el at the end of the queue
– dequeue() — Take the first element from the queue
– front() — Return the first element in the queue without
removing it
• Exceptions
– Attempting the execution of dequeue or front on an empty
queue throws an EmptyQueueException
sometimes the peek() is named instead of front().
6. Data Structures and Algorithms in Java 6/21
Applications of Queues
• Direct applications
– Waiting lists, bureaucracy
– Access to shared resources (e.g., printer)
– Multiprogramming
• Indirect applications
– Auxiliary data structure for algorithms
– Component of other data structures
7. Data Structures and Algorithms in Java 7/21
Application: Round Robin Schedulers
We can implement a round robin scheduler using a queue, Q,
by repeatedly performing the following steps:
1. e = Q.dequeue()
2. Service element e
3. Q.enqueue(e)
The Queue
Shared
Service
1. Deque the
next element
3. Enqueue the
serviced element
2. Service the
next element
Round-robin (RR) is one of the simplest scheduling algorithms for processes in an
operating system, which assigns time slices to each process in equal portions and in
circular order, handling all processes without priority. Round-robin scheduling is both
simple and easy to implement, and starvation-free. Round-robin scheduling can also be
applied to other scheduling problems, such as data packet scheduling in computer
networks.
The name of the algorithm comes from the round-robin principle known from other fields,
where each person takes an equal share of something in turn
Round Robin Schedulers
8. Data Structures and Algorithms in Java 8/21
Array-based Queue - 1
• Use an array of size N in a circular fashion
• Two variables keep track of the first and last
f index of the front element
l index of the last element
Q
0 1 2 l
f
normal configuration
Q
0 1 2 f
l
wrapped-around configuration
Array-based Queue
9. Data Structures and Algorithms in Java 9/21
Array-based Queue - 2
Array-based Queue in detail
10. Data Structures and Algorithms in Java 10/21
Array implementation of a queue - 1
10
class ArrayQueue
{ protected Object [] a;
protected int max;
protected int first, last;
public ArrayQueue()
{ this(10);
}
public ArrayQueue(int max1)
{ max = max1;
a = new Object[max];
first = last = -1;
}
public boolean isEmpty()
{ return(first==-1);}
public boolean isFull()
{ return((first == 0 &&
last == max-1) || first == last+1);
}
private boolean grow()
{ int i,j;
int max1 = max + max/2;
Object [] a1 = new Object[max1];
if(a1 == null) return(false);
if(last>=first)
for(i=first;i<=last;i++) a1[i-first]=a[i];
else
{ for(i=first;i<max;i++) a1[i-first]=a[i];
i = max-first;
for(j=0;j<=last;j++) a1[i+j]=a[j];
}
a = a1;
first = 0;
last = max-1;
max = max1;
return(true);
}
11. Data Structures and Algorithms in Java 11/21
Array implementation of a queue - 2
11
void enqueue(Object x)
{ if(isFull() && !grow()) return;
if(last == max-1 || last == -1)
{ a[0] = x; last=0;
if(first==-1) first = 0;
}
else a[++last] = x;
}
Object front() throws Exception
{ if(isEmpty()) throw new Exception();
return(a[first]);
}
public Object dequeue() throws Exception
{ if(isEmpty()) throw new Exception();
Object x = a[first];
if(first == last) // only one element
{first = last = -1;}
else if(first==max-1)
first = 0;
else
first++;
return(x);
}
12. Data Structures and Algorithms in Java 12/21
Linked list implementation of a queue
12
class Node
{ public Object info;
public Node next;
public Node(Object x, Node p)
{ info=x; next=p; }
public Node(Object x)
{ this(x,null); }
};
class MyQueue
{ protected Node head,tail;
public MyQueue()
{ head = tail = null; }
public boolean isEmpty()
{ return(head==null);}
Object front() throws Exception
{ if(isEmpty()) throw new Exception();
return(head.info);
}
public Object dequeue() throws Exception
{ if(isEmpty()) throw new Exception();
Object x = head.info;
head=head.next;
if(head==null) tail=null;
return(x);
}
void enqueue(Object x)
{ if(isEmpty())
head = tail = new Node(x);
else
{ tail.next = new Node(x);
tail = tail.next;
}
}
13. Data Structures and Algorithms in Java 13/21
A Circular Queue
In previous chapter , we implemented a circularly linked list class that supports
all behaviors of a singly linked list, and an additional rotate( ) method that
efficiently moves the first element to the end of the list. We can generalize the
Queue interface to define a new CircularQueue interface with such a behavior, as
shown below:
public interface CircularQueue extends Queue {
/*Rotates the front element of the queue to the back of the queue.
This does nothing if the queue is empty.*/
void rotate( );
}
A Java interface, CircularQueue, that extends the Queue ADT with a new rotate( )
method. This interface can easily be implemented by adapting the
CircularlyLinkedList class to produce a new LinkedCircularQueue class. This class
has an advantage over the traditional LinkedQueue, because a call to Q.rotate( )
is implemented more efficiently than the combination of calls,
Q.enqueue(Q.dequeue( )), because no nodes are created, destroyed, or relinked
by the implementation of a rotate operation on a circularly linked list.
A circular queue is an excellent abstraction for applications in which elements are
cyclically arranged, such as for multiplayer, turn-based games, or round-robin
scheduling of computing processes.
14. Data Structures and Algorithms in Java 14/21
Queue Interface in Java - 1
• Java interface
corresponding to our
Queue ADT
• Requires the
definition of class
EmptyQueueException
• No corresponding
built-in Java class
public interface Queue {
public int size();
public boolean isEmpty();
public Object front()
throws EmptyQueueException;
public void enqueue(Object o);
public Object dequeue()
throws EmptyQueueException;
}
15. Data Structures and Algorithms in Java 15/21
Double-Ended Queues (Deque) - 1
15
We next consider a queue-like data structure that supports
insertion and deletion at both the front and the back of the queue.
Such a structure is called a doubleended queue, or deque, which
is usually pronounced “deck” to avoid confusion with the dequeue
method of the regular queue ADT, which is pronounced like the
abbreviation “D.Q.”
The deque abstract data type is more general than both the stack
and the queue ADTs. The extra generality can be useful in some
applications. For example, we described a restaurant using a
queue to maintain a waitlist. Occasionally, the first person might be
removed from the queue only to find that a table was not available;
typically, the restaurant will reinsert the person at the first position
in the queue. It may also be that a customer at the end of the
queue may grow impatient and leave the restaurant.
16. Data Structures and Algorithms in Java 16/21
Double-Ended Queues (Deque) - 2
16
The deque abstract data type is richer than both the stack and the queue
ADTs. To provide a symmetrical abstraction, the deque ADT is defined to
support the following update methods:
addFirst(e): Insert a new element e at the front of the deque.
addLast(e): Insert a new element e at the back of the deque.
removeFirst( ): Remove and return the first element of the deque (or null if
the deque is empty).
removeLast( ): Remove and return the last element of the deque (or null if
the deque is empty).
Additionally, the deque ADT will include the following accessors:
first( ): Returns the first element of the deque, without removing it (or null if
the deque is empty).
last( ): Returns the last element of the deque, without removing it (or null if
the deque is empty).
size( ): Returns the number of elements in the deque.
isEmpty( ): Returns a boolean indicating whether the deque is empty.
17. Data Structures and Algorithms in Java 17/21
Priority Queues
17
• A priority queue can be assigned to enable a
particular process, or event, to be executed
out of sequence without affecting overall
system operation
• FIFO rule is broken in these situations
• In priority queues, elements are dequeued
according to their priority and their current
queue position
18. Data Structures and Algorithms in Java 18/21
Array implementation of a priority queue - 1
18
class PriorityQueue
{ protected float [] a; int top, max;
public PriorityQueue()
{ this(50);
}
public PriorityQueue(int max1)
{ max = max1;
a = new float[max];
top = -1;
}
protected boolean grow()
{ int max1 = max + max/2;
float [] a1 = new float[max1];
if(a1 == null) return(false);
for(int i =0; i<=top; i++)
a1[i] = a[i];
a = a1;
return(true);
}
public boolean isEmpty()
{ return(top==-1);}
public boolean isFull()
{ return(top==max-1);}
public void clear()
{ top=-1;}
public void enqueue(float x)
{ if(isFull() && !grow()) return;
if(top==-1)
{ a[0] = x; top = 0;
return;
}
int i = top;
while(i>=0 && x<a[i])
{ a[i+1] = a[i];
i--;
}
a[i+1] = x; top++;
}
19. Data Structures and Algorithms in Java 19/21
Array implementation of a priority queue - 2
19
public float front()
{ assert(!isEmpty());
return(a[top]);
}
public float dequeue()
{assert(!isEmpty());
float x = a[top];
top--;
return(x);
}
20. Data Structures and Algorithms in Java 20/21
Summary
20
• A queue is a waiting line that grows by adding elements to its
end and shrinks by taking elements from its front.
• A queue is an FIFO structure: first in/first out.
• In queuing theory, various scenarios are analyzed and models
are built that use queues for processing requests or
other information in a predetermined sequence (order).
• A priority queue can be assigned to enable a particular
process, or event, to be executed out of sequence without
affecting overall system operation.
• In priority queues, elements are dequeued according to their
priority and their current
queue position.
21. Data Structures and Algorithms in Java 21/21
Reading at home
Text book: Data Structures and Algorithms in Java
• 6.2 Queues - 238
• 6.3 Double-Ended Queues (Deque) - 248
• 9.1 The Priority Queue Abstract Data Type - 360