Questions tagged [java]

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27 views

Modifying relaxation for the Bellman-Ford algorithm [closed]

I'm using the Bellman-Ford algorithm to find the best path in my graph. However, instead of choosing the path with the lower value, I want to choose the path with the highest value. And instead of ...
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1answer
23 views

In what sense if any does java have multiple dispatch?

I'm trying to get my head around the difference between message passing (with which we are all familiar as by far the most common form of object orientation today) vs generic functions as implemented ...
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1answer
29 views

Sum of unique integers to cnf constraint

As a study project I try to solve the kakuro puzzle problem using SAT SOLVER. I can't really find an efficient way to convert the sum of k unique integers (1...9) to a CNF constraint. What I had in ...
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10 views

Processing RSS content from different providers based on priority

I have multiple RSS provider URLs. Each RSS provider posts articles from time to time. Each article has a published date. Some RSS providers post more often than others. I have to go through the list ...
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1answer
43 views

What is a constructor in java? [closed]

I have checked many websites but did not get the right answer. what is the meaning of constructor in java?
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1answer
90 views

Linked list: advantages of preventing movement of nodes and invalidating iterators on add/remove

C++ and Java include native classes for linked lists, C++ std::list and Java LinkedList For C++ std::list, nodes can be "moved" within a list, or from list to list (if the lists are compatible), via ...
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27 views

What is the difference between self-rewriting program and program-with-updates-and-restart

I am reading about Goedel machine http://people.idsia.ch/~juergen/goedelmachine.html and especially the article about possible implementation (in the Scheme language) of this machine http://people....
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61 views

Given n strings, how to output their order after k phases of the radix sort (huge constraints)?

Disclaimer This is not from an ongoing contest, this is from my course of ITMO on edx.org, which is a paid code so I cannot give you a direct link to the course. Problem You are given $\...
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1answer
76 views

Is there any way to find the nodes in the each subtree of each node having distance equal to height of the subtree?

We are given a tree of N nodes from 1 to N where node 1 is the root of the tree. For each node i from 1 to N, you have to find the numbers of nodes which are in the subtree of i and are at distance ...
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1answer
27 views

Count of (x,y) pairs that satisfy the equation x^2+y^2 = n^2

Given (n) , what is the Count of (x,y) pairs that satisfy the equation x^2+y^2 = n^2. Is there any way I can re-write this code just without using nested loop? ...
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16 views

Java configuration for int-amqp [closed]

I am trying to convert a XML based configuration to JAVA based configuration. Can someone please let me know the java annotation based configuration for the following ...
2
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1answer
118 views

Find path from node

I have a question where I need to find a path from node 1 to node N in an undirected graph given weights in O(A Log^2 A). The total cost of each path must not ...
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1answer
21 views

How does the instanceof operator work in the context of downcasting in java? [closed]

I am trying to understand the purpose of using the instanceof operator as a way to properly downcast an object in java. I really hope someone can help. Below is more code: ...
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26 views
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3answers
48 views

Write a routine to print the numbers 1 to 6 and back to 1 again without using any loops [closed]

Can anyone help with this question? I currently have this solution that prints 1 2 3 4 5 6 but I'm having trouble going back down to 1. ...
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1answer
41 views

Why whenever a caller or client modifies a library collection class, all iterators are made invalid? [closed]

Whenever a caller or client modifies a library collection class, all iterators are made invalid (with the exception of the iterator through which the change was made, in the case of remove). Give a ...
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2answers
180 views

algorithm to find all values that occur more than n/10 times

I took an algorhytm course on coursera and there some optional questions for student enrichment. I can't solve the following task: Decimal dominants. Given an array with n keys, design an algorithm ...
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1answer
104 views

Which Data Structure should I use to store words from a novel?

So, I was learning Data Structures in Java on my own. And there was a "challenge question" in the book. The question basically asked me to make a data structure that could store all the words in a ...
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1answer
44 views

Please help, I have been attempting to understand Quicksort for 9 hours now with little luck!

I have done absolutely everything that i could to try to understand this algorithm. I did NOT want to go on without understanding it completely even though I know it might only be a single problem in ...
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0answers
23 views

Nested Function stuck on iteration update

I want to solve the Sparse Extended Information Filter Slam described by Dr. Sebestian Thrun in Probabilistic Robotics.I stuck in some nested function. The algorithm is described in page 309 in this ...
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2answers
7k views

How is the formula for calculation in row/column major obtianed?

In my book, this formula is given for calculation of address of row major order's element $[I,J]$: Address of $[I,J]$th element in row major order $= B + W[n(I-L_r)+ [J-L_c]]$ where B denotes base ...
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1answer
39 views

Construct an array from a binary tree

I am looking for a suggestion. I know it is possible to construct a binary tree from an array. I want to know that vice verse is true? Is it possible to construct an array from a binary tree? If yes ...
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1answer
43 views

Linked List fundamental concepts [closed]

I am trying to understand the basics of Linked List. The definition of my LinkedList class is as follows: ...
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1answer
42 views

Beginner question in Java [closed]

I am just starting to study Java and was wondering why the following code if(x>2) x*=2; if(x>4)x=0; System.out.println(x); returns 0 for any value of x greater than 2. For example, when x=3, why ...
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1answer
425 views

Knapsack progblem with two conditions

I want to create an algorighm (with dynamic programing) similar to 1/0 knapsack problem but, I have one extra condition isVegetable or isFruit. Assume we have N food items where we know ...
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1answer
319 views

What is the time complexity of this Factorization program?

input: n-bit integer X output: list of prime factors and their multiplicity acc = X ...
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1answer
32 views

Algorithm to select sets of objects while maximizing number of objects covered

If we have different objects, [A1, A2, A3, B1, B2, B3, B4, B5] Some calculations will be performed to find compatible objects. For example, lets assume following ...
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250 views

I'm looking for best algorithms to compare two Circular Linked List?

I'm looking for best algorithms to compare two Circular Linked List? For example : List 1 = 1-3-5 List 2 = 3-5-1 I want to compare "same" or "not same" but need fast algorithm.
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2answers
152 views

Formal model of execution for Java (or general imperative language)

I'm trying to prove some statements about execution in Java programs under some heavy restrictions (basically I have a conjecture that if two methods satisfy a set of constraints for a given input ...
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0answers
140 views

Novel escape analysis algorithm for Java

Today I read a very interesting article about escape analysis in Java called Escape Analysis for Object Oriented Languages: Application to Java I think I have some grasp on how escape analysis works ...
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2answers
100 views

How do compilers implement symbolic (rather than textual) insertion?

From a programming language designer's point of view, how is "symbolic" insertion implemented as opposed to "textual" insertion using pre-processor macros? I understand the basics of how "textual" ...
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4answers
129 views

what is the complexity of this program? [duplicate]

// assume 'n' is given. What is the time complexity of this code ? ...
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0answers
154 views

Is the Java 8 Grammar still a LALR(1) grammar?

As I found out here: http://www.eclipse.org/jdt/core/howto/generate%20parser/generateParser.html , the Java Version of 2005 (might be Java 6, I'm not sure) is a LALR(1) grammar. However, I couldn't ...
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1answer
549 views

What fragment of Martin-Löf dependent type theory can be expressed using generic types in Java?

I have recently come to realize that a number of problems I had a few years ago trying to implement various mathematical theories in Java came down to the fact that the typing system in Java is not ...
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1answer
1k views

How does recursion work in void method java [closed]

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17 views

Without sound synthesis, what is a good way of making a program that plays guitar notes from an array of stored sounds?

Without sound synthesis, what is a good way of making a program that plays guitar notes from an array of stored sounds? What I have in mind is to make note as a function of vibration speed such as N (...
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1answer
206 views

What is the O time complexity for this algorithm?

is the Big-O for this O(1) or some asymptotic like 1/n? Saying that because if it defaults, the time limits at about 1000000 ns, but if it returns while in the loop, it is about a fraction of that. ...
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1answer
168 views

How to calculate the average of x numbers? [closed]

I just started a college course and I'm being asked for a flowchart where I explain how to calculate the average of x quantity of numbers. For this assignment I'm asked to follow the problem solving ...
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2answers
470 views

Version of knap sack problem

The are cuisenaire rods with N differnt lengthes $x_1,x_2,...,x_n$ (each length is a natural number), the number of the Cuisenaire rods is unlimited. Given a natural number B. you should tell if you ...
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1answer
71 views

Can local variables be instance variables? [closed]

I know that variables can be categorized in two ways:- The first way is to classify them into global and local variables based on their scope. When the variable is accessible by all the functions of ...
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2answers
5k views

Find out duplicate number between 1 to N numbers

I first saw this question on this website where I was trying on Java puzzles. Here is the Question:- ...
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1answer
706 views

Which is the best data structure for searching under these conditions

I have a system with some factors, say A, B, C, and D. There can be different values of all these factors. Let us consider few values to have a better understanding. Let's say A has 4 different ...
2
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2answers
400 views

Binary Search Tree Traversals

I have a clue as to how this code/traversals work but I'm still confused. For example, in the first traversal (Preorder), it prints 31, 12, 25 but then it backtracks all the way to 68? How does it ...
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1answer
40 views

Is there a general pattern/structure/format to most (if not all) computer functions?

First time posting. I know this is a very generalized question, sorry for that, I don't know how to more appropriately word this. I've noticed a tread, a pattern in methods, it seems in almost all ...
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1answer
50 views

Inheritance problem (JAVA) [closed]

Here I have created 2 classes , $A$ is the super class of $B$ , i.e , $B$ inherits the features of class $A$. Now I don't know exactly what statement (1) does but I am speculating as follows ,kindly ...
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0answers
277 views

Normal Distribution pattern in Java Array of doubles

Given ordered array of float numbers, Check if array represents Normal Distribution. I wrote algo to find triangular distribution as follows: ...
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0answers
194 views

Are type constructors always injectives even in presence of quantified type variables (subtyping)?

Are type constructors, in a language that feature subtyping and quantification of type variables, like scala or Java, always injective? That is, is an equivalent of haskell ...
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1answer
3k views

improving java 8's implement to hash map using avl tree

Java 8 got a new implement to hashmap (using a tree). I have understand that in the worst case, it may be O(n) for lookup. Will changing this implement to an avl tree change this O(n) case to ...
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1answer
62 views

Why does this statement evaluate to 176? [closed]

int y = 10; int z; z = (++y * (y++ + 5)); // Evaluates to 176 According to me this should evaluate to 180. Please provide an explanation as well which relates to ...
2
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0answers
86 views

Byte Code/IL Code execution [closed]

I understand that Byte/ IL Codes are interpreted/executed by their corresponding run times. Do those run time converts the Byte/IL codes directly to machine code which processor can execute or the ...