A stack is a last in, first out (LIFO) abstract data type and data structure. Perhaps the most common use of stacks is to store subroutine arguments and return addresses.

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Stack implementation with exceptions [on hold]

I would like to know if this is a great stack implementation. I created my own exception. Was that a bad idea or unnecessary? Should I have just thrown a IndexOutOfBounds exception instead of my own. ...
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Proper Stack Implementation

I want to know if this stack is implemented properly. Previously I was told a Linked List contains an inner class that represents a node and the outta class that represents the structure. Does that ...
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Managing a programmatically accessible stack trace

VBA has a call stack... but there's no programmatic way to tap into it, which means in order to get a stack trace for a runtime error, one has to manage it manually. Here's some example code that ...
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Designing stack and queue from scratch in C

As a beginner and curious guy I'm interested in implementing data structures and algorithms from scratch. Here's my implementation of Stack and Queue, the most fundamental data structures. Are ...
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1answer
64 views

Implement a queue using two stacks

I tried to implement a queue using two stacks. I saw there are questions about this topic, but in my example, I used build-in stack from java. My question is, can someone give me some advice to make ...
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124 views

Poisonous Plants

I have solved the following problem. My code works but Hackerrank says that I can do faster: There are plants in a garden. Each of these plants has been added with some amount of pesticide. ...
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Finding the Least Common Ancestor of a Binary Tree

Input a binary tree (the root node) and 2 other nodes that need to be assessed for finding the least common ancestor (LCA) Code: a. Finding the nodes first with either ...
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Queue using Stack

I implemented this solution for the problem. Please provide feedback and review if this can be improved in any way. ...
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67 views

Stack from Linked List

I have written a program that takes a linked list and then converts it to a stack. I would like a code review for my program. Thanks in advance. Stack.java ...
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Improving time efficiency of finding maximum area rectangles in a histogram

Here's my solution but I am looking for ways to improve the time complexity of solution. Also this question is categorized as being solved by stack so I would like to know how to approach it using ...
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42 views

Stack that does Push, Pop and Median in O(1)

Here are two implementation of a stack that does Push, Pop and Median in O(1). Invite comments on complexity and betterment. Option - 1 ...
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158 views

Reverse Polish Notation Evaluation in Java

I would like to hear feedback about my code both in term of improving efficiency if possible or using other data structures. Also go ahead and let me know about code styles/patterns. ...
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1answer
43 views

Queue implementation using two stacks

Here's my code and I want to know if there's a better method for doing so. While the question has stated two stacks I wonder if we could do only with one as well? ...
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53 views

Building a Stack with C structs

After reading the book from which this example is from I started using APIs like this ...
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C++ Dynamic array based stack

This is my first post so if I am doing something wrong in the post please let me know. I have implemented a dynamic array based stack. Can someone point out any pitfalls or things that can be done ...
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53 views

Sort stack using two stacks

My program is supposed to sort a stack such that the smallest item are on the top. I can use a temporary stack, but you may not copy the elements into any other data structure. The program works ...
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Mergesorting a stack in Java - a new algorithm

(See the previous iteration.) Now I have implemented a stack merge sort that does not have to reverse every substack after sorting it, and it allocates the two auxiliary stacks only once prior to the ...
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1answer
64 views

Mergesorting a stack in Java

(See the next iteration.) I have this small program for sorting a stack using mergesort. Basically, the aim was to use as little aid from JDK library as possible. See what I have: StackMergesort....
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Sort a stack in descending order

Maintain current element as the top element in the input stack. Pop all the elements on the ordered stack which are greater than the current element and push them in to the input stack and maintain a ...
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Stack based esoteric language interpreter in Ruby

For a while now, I've wanted to write a stack-based "Turing-tarpit". This is the perfect excuse to learn Ruby, which I have never used before, so I wrote Brain-flak. The language only uses these ...
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Three stacks in a single array

I have implemented three stacks in a single array in Java. Any advice on object oriented design, coding structure, logical part or any sort of advice would be appreciated. ...
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166 views

Find minimum node in Linked-List

I wrote a method that will return the minimum element in a linked-list that operates in O(1) time. I tested and everything works fine. However, I was wondering if there is anything that I can do to ...
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C stack for Linux and BSD

My stack uses char data and is not tested. I use it to save command in a unix pipeline for my own POSIX shell. Maybe you can find a bug or a possible improvement. ...
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1answer
90 views

Dynamic array stack and bag implementation

I've have methods for a stack and bag using a dynamic array in C. As far as I can tell everything is implemented correctly, but I'm wondering what I can do to improve this code. dynArray.h ...
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1answer
63 views

Stack implementation using a growing array

I'm working through Sedgewick's Algorithms book for fun and educational purposes. I am implementing a simple Stack<T>, using ...
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1answer
86 views

Balanced parenthesis in Ruby

I'm solving the "Balanced Parenthesis" problem in Ruby, and I came up with this solution. ...
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Stack and Queue implemented with a LinkedList

I am looking for feedback on my implementations of Queue, Stack, and LinkedList using Java ...
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181 views

Fuzzy Octo Guacamole interpreter

This is my code that interprets my own golfing and esoteric language, Fuzzy-Octo-Guacamole. It has 2 stacks to store information in, and various operations can be performed on each stack, or both at ...
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Comparing a string using a stack

Let L be the language defined as follows: The words are made up of strings of a’s followed by b’s. The number of a’s is always equal to the number of b’s. Examples of words that belong to ...
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Fixed-length Stack in Java

I implemented a fixed-length stack in Java for use in my fractal generator program, an RPN calculator and my esolang interpreter. This is a generic stack, and goes over and above the call of duty in ...
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Java Stack Implementation with Generics

I've written an implementation of a Stack data structure using a linked list. Stack.java ...
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Checking for matching delimiters using multiple stacks or counters

I know my algorithm is very naive and slow for this problem. I would like to learn how to improve upon it? ...
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58 views

Custom concurrent stack implementation in Java

I don't want to use synchronized for sizeof method, any suggestion to implement the method thread safe? ...
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2answers
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Program looks for correct balance of ( [ and { in expression

I'm still new to programming. (First exposure was school about a year ago), and for some reason this problem really gave me a lot of problems trying to solve it. Can you help me understand what I ...
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1answer
120 views

Tail-recursive call vs looping for a Poker app

I'm developing a Poker app. It is almost done, and I'm looking for improvement. One of the things I wonder is whether I should change how I perform iterations. I currently iterate by using tail-...
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2answers
91 views

Templated Stack of 5

This is my first time using C++ Templates to make a data structure. I have written a program to implement a stack of up to 5 items. ...
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3answers
124 views

Sort stack in ascending order

I am using two more helper stacks to sort. Kindly suggest improvements in terms of space and time. ...
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43 views

Implement MyQueue using two stacks

I am taking a helper stack, which is used during dequeue. Kindly suggest improvement or some solution with less complexity. ...
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Stack having push, pop and return min in O(1)

I am using a class which is taking care of minimum value so far. Please let me know of any improvements or suggestions. ...
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260 views

Reverse Polish Notation Calculator in Java

I created a highly effective Reverse Polish Notation calculator using Java 8, but am uncertain if there are any better ways to handle the problem. Feedback on any evident taboos and bugs is greatly ...
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Implementing Multi-File Programs in Vitsy

I'm the proud owner of the Vitsy programming language, which I've been working on for some time (except recently, because high school). It's only been used in PPCG so far, but I hope to expand it to ...
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Implementation of stack

Task: Create a class RPNStack which represents a stack of objects of type Node. Class RPNStack contains only one private field top of type Node. Objects of type Node represent data that are ...
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1answer
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Simple stack structure in C

I just started to learn C, and for practicing, I tried to implement a simple stack data structure, and I want to know if I'm making any mistakes, or how could I improve it: My stack.h: ...
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C Stack data structure

I have implemented a Stack data structure in C and I would like to know if there is something that could be improved. Stack using linked list: ...
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210 views

Sort a stack of numbers in ascending order only using push

I have a stack of numbers ranging from 1 to 1 million representing a pile of numbered DVDs. Given the stack in random order I am to sort the stack by only taking an element from the stack and push it ...
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Given a path to a directory, print the path to the biggest file in it

Here is my code. I simulated a stack rather than used some regular recursive algorithm because I needed to keep track of two variables: the path to the biggest file and its size. Besides I wrote a few ...
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1answer
108 views

Mutable stack in Racket

I'm learning Racket and have implemented a mutable stack, which is just a bunch of wrappers around an underlying struct containing a size and buffer list (so it's ...