Questions tagged [deque]

A double-ended queue. Container datatype which is typically supporting efficient insertion and removal from two ends.

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Why can't I access the size of this C++ array?

I am new to C++, and I am trying to write a function to solve this challenge. The code I have looks like this: #include #include #include using namespace std; void printKMax(int arr[], int n, int k){ deque
adam tropp
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Average of last 6 elements from given element in list

I have list=[307, 258, 164, 193, 174, 285, 230, 160, 257, 306, 173, 169, 192, 209, 110] I want to calculate average last 6 elements from given element[n] in list and after that n should iterate by 1[n+1] and again same operation should…
trupti
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Convert deque to Json

I have a server that reveives a set of data like this : ['Date(yyyy - mm - dd)', 'Time', 'Conductivity(mS / cm)', 'Temperature(C)', 'Depth(m)', 'Battery(V)', 'Salinity(PSU)', 'Density (kg m-3)', 'Calc, SV (m/s)'] ['18/01/2017', '08:04,3', '12,217',…
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Double Linked Queue with specific template

I have the intention to do a program based on a Double Linked Deque where nodes have double links and what i want to do is that each node is a "Document with name and priority" (priority = 1 insert from head, prio. = 2 insert from rear). Actually…
Arnau Martínez
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I'm implementing a deque using singly linked list in Java. My addLast() is not working

I'm implementing a deque using singly linked list in Java. My addFirst() function is working fine, but addLast() is not working. Whenever I call addLast(), I got the following error message: java.lang.NullPointerException
Zhengxi Tan
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Need an understanding on deque

I do not understand how for d[5] the answer is C. I am trying to understand lists in C++ but for some reason this concept escapes me. Can anyone explain why C is the correct answer? The following represents output from the call d.Dump() from…
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Fastest way to add a deque onto the end of a vector?

This question is about speed. I am using a function in the openCV libraries (in FaceRecognizer class) which requires the input of a vector. I need to build this vector by combining several deque. Are there any faster ways other than iterating…
wprins
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Null pointer exception while dequeing Queue in java

My dequeue method : public T deQueue(){ if(isempty()){ System.out.println("Queue is empty, cant dequeue"); }else if(front==rear){ T value=queue[front]; front=-1; rear=-1; …
Arun Prakash
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Dequeue class printing address instead of QueueNode item

I'm trying to create a Linked List dequeue class that accepts nodes at the head as well as rear. My method, tailRemove() should remove only the item at the tail of the deque. However, when I print it, it's printing the address. The toString() method…
srsarkar7
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Memory fault in C++ program seemingly caused by deque

I am building a small C++ program that needs to use a deque to manage some dynamic data. I built the script and works great when there are small amounts of data put in and taken out of the deque, but when a good amount of data is put in and out the…
chromedude
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Is this valid when dereferencing an iterator

for (auto iter = dlQueue.cbegin(); iter != dlQueue.cend(); ++iter) { // reference to the current element in the container if (*iter.id == listid) { *iter.stall =…
TheBlueCat
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deque prints back element instead of the front using front()

I am using dque to push some elements that I read from a file to the back of the deque but when I print them from the front I only get the last element fgets(line,100,file); qu.push_back(line); fgets(line,100,file); qu.push_back(line); …
Roola
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comparison between pointers

I am implementing a dequeue in c via arrays. left and right are pointers which point to the leftmost and rightmost elements of the dequeue. The show() function recieves the left and right pointers. When i try the following in void show(int *l,int…
ksb
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implementation of dequeue in python using linkedlist

I implemented a Dequeue using a simple list in python. However i need to implement a separate class for linked list and implement dequeue with that. For this pointer reference is needed at left and right ends. I don't know how to do this. Can some…
kiran
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deque implementation details

I am reading article about the implementation of deque(Deques) Here is the corresponding code: template class deque { public: ⋮ private: size_type theSize; T** blockmap; size_type mapSize; …
Vardan Hovhannisyan
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