Questions tagged [performance]
Performance is a subset of Optimization: performance is the goal when you want the execution time of your program or routine to be optimal.
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Inserting data into SQL-Server table dynamically
I know I can do all this via SSMA quite quickly, but I wanted to see if I could do it efficiently in PowerShell myself as a little project.
Basically, the entire script takes tables from an Access ...
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2D Matrix with jagged array isn't faster than one with a multidimensional array
I was trying to use Math.Net's dense matrix class. But, it doesn't support int. So, I have to create a wrapper for a jagged 2d array.
I knew that jagged arrays ...
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Efficiently sample a single row of an array at random
I have the following C++ code snippet that randomly samples a single row in an array called pop with num_specs columns and ...
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Optimizing loop - Reducing native calls
I am developing Android-Disassembler.
I need to optimize the loop below.
It is currectly calling native method for each instructions(about 4 bytes). So this loop will be looped about millions of ...
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Using Reflection to call multiple methods and cast various classes [closed]
I have written the following Reflection code:
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Encoding and decoding log entries in a Lossy Binary Format
One of the projects I'm working on requires logging a huge amount of information (basically, every function call). The problem is obviously that logging a lot of information has a few side-effects, ...
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Loading items into array from SQL Server [closed]
The program we are working at has the following function:
...
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Method that receives a hexadecimal string and returns a formatted matrix of those values
This method is part of a larger project and comes after encoding ascii characters into hexadecimal values, so it assumes the parameter is always a valid hex string.
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Check if a string is a valid english word, and convert to a valid english word
This is an interview question.
For the purpose of the question, a valid English word is a string that begins with an uppercase English letter, and the rest of the string contains only lowercase ...
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Looping text with directional control
The code is an implementation of looping text (similar to a circular buffer - wraps around when it reaches the edge of the defined bounds) with directional control.
The code is functional and works ...
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Finding the name of a given constant using reflection
The code below comes from the Arm_const class of my Android disassembler project:
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Looping text in Python with directional control
The code is an implementation of looping text (similar to a circular buffer - wraps around when it reaches the edge of the defined bounds) with directional control.
The code is functional and works ...
user180837
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Search for rows in a 2D array that contain a given sequence
I have a 2d array of m * n dimension (m and n can vary from 1 to 100000). The following snippet of code checks if the sequence exists in the row and stores the index if it exists. The time taken by ...
user180762
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Hash table, using special values to mark empty and deleted indexes
The following is a program for my school. It's supposed to use a hashtable to store values/keys. We use a marking system to mark for empty indexes and deleted indexes. -1 for empty and -2 for deleted. ...
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Hungarian algorithm to perform least-cost assignments
The Hungarian algorithm solves the assignment problem, and I'm looking for
any suggestions regarding improvement on my implementation (also coding style). It is based on the wikipedia entry and ...
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Comparing two large binary files in C
I'm trying to read two sufficiently large binary files, comparing them and printing the offset at which they differ. I'm using fread to read the binary files and <...
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Word search algorithm
I have a Word Search algorithm, the main function (wsearch) takes a grid of letters as an input and a 'word' to search for. The output is the number of occurence of ...
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Modeling a capacitor with DC Bias
I am modeling a capacitor which has its capacitance varying according to the DC Bias. The DC Bias is computed by taking the mean of the voltage across the capacitance.
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Reading a gzipped file with JSON data for thousands of users
I'm a newbie in Python.
I need to read a GZ file contains thousands of users.
But I think my code is not optimized in this case. Could anyone can help me? What should I do to improve performance? Or ...
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Javascript code to make Matrix wallpaper [closed]
I am a javascript noob. I did this program for the sake of learning javascript in a better way. the code is to display matrix live wallpaper in the browser.
Here is the code
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Counting integers that are within intervals
I am looking for a more efficient way than bruteforcing my way through in the following problem in python 3.
Problem statement:
Input:
An array of n integers, scores, where each score is denoted by ...
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Checking if a number is divisible by 2-11
I am writing a Python class which checks if a given number is divisible by numbers 2-11. I am not using the __init__ method which in my opinion is not necessary in ...
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Determinant using Gauss Elimination
We had a question in examination to compute determinant of general square matrix.
Now I had made the normal program using Laplace Formula of determinant, ie, recursive solution.
Now I was thinking of ...
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Font and color checker chrome extension in JavaScript
I have written this code for a color and font checker on a webpage.
The code is current and not so good. I would really like if I can get comments, reviews or any better approach for my PoC.
PoC: I ...
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When given 7 letters, find all possible words with length 3 to 7
I am writing a program in JavaScript to find all possible words given 7 letters. The words have to be 3 or more characters, and for right now I am limiting it to 7 characters long. The code below ...
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Copying contents between BufferedStreams in Java
This is a simple function that copies the content of one stream to another. My question is simple. I am currently, copying between the streams one byte at a time, but the streams are both Buffered. ...
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Intersection over Union for rotated rectangles
Problem Statement
I am trying to find the intersection over union (IoU) metric for one to several rotated rectangles compared to many different rotated rectangles. Here are some images to help ...
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Iteratively simulate a parasite population
I'm trying to build a simulation in R to model the effects of different parasite egg laying behaviors on how many offspring the parasite has, given a limited amount of resources. In brief, this ...
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Insert items from one table that do no exist in the other one [closed]
The insert query below must insert the items not present in the Articolo table by importing them from Importazione, and must update the items in the Articolo with those present in the Importazione. To ...
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Sorting CSV table in Powershell
I'm wondering if some PS gurus can advise on whether my method for sorting and recombining some data fields by using an array of PSCustomObjects is as efficient as it might be.
I'm importing a CSV ...
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Decoding a string encoded by Caesar Cipher and some delimiters [closed]
I have the following code which I seek to optimize. The result of the bruteforce I already have but I'm just trying to learn some more python using the same example.
The code in the data needs to be ...
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Reads paragraphs of common artists separated by commas
I want to make this faster, I'm not a great coder and just want to learn. This program reads paragraphs of common artists separated by commas. The user inputs the name of a desired artist and the ...
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String search algorithm for finding if a long list of long strings string exists in a similarly sized haystack
My use case is that I have a list of emails and I need to find if the email is in the chain:
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Number factor of a number
I currently have a number factors program that performs the following things: The user enters a number, checks whether it is a perfect square (yes or no), prints the square root if it is a perfect ...
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Effieciently validate multiple DataRows with return early option
I'm looking for an efficient way to validate multiple rows originating from multiple .csv files. Below is the current code to accomplish that.
The validation logic is in the function ...
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check if two elements exist in array with older browser support [closed]
Currently I have this code
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Group-wise deviations from means / centering with dplyr vs. data.table
I am trying in R to "center" a matrix (i.e. remove mean) group-wise (i.e. remove group means for each variable).
Input is a matrix (including the grouping variable), and output is the same matrix, ...
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Pairwise adding tuples in a list
I have two list of tuples:
[[1,8],[2,7],[3,14]]
[[1,5],[2,10],[3,14]]
and a desired sum 20. I need to find two tuples from two list whose second element either ...
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Merge both sql queries into one to get the performance
Currently i am using 2 queries - one for reattemptdate & one for holddate.... if we merge both queries & get the results in single query , than will it give better performance? if so how to ...
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Extract a box with pixel values from an image, calculate the mean of each possible box [closed]
I have a two-dimensional array with M rows and N columns, with each element having a value between 0 and 255.
I have a second two-dimensional array with m rows and n columns, m < M, n < N.
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Tracking employee data
We have hundreds of employees and for tracking each employees' data, and I am using this code:
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Index Match implementation
The code below takes header variables, retrieves the column index, and then, using an Index/Match function, returns data from a matching account number.
The reason it is written this way is because I ...
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Odd Even Subarrays
I've been trying to understand Dynamic Programming lately, here's the question I just attempted:
You are given an array A of N positive integer values. A subarray of this array is called an Odd-...
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INCARDS SPOJ challenge
Question-
In short question says that you have N bus stops and K bus routes.
Every bus routes is linked to two bus stops. Each route has some cost
of travelling. It says one person visit any ...
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Optimizations of C Code - Bilateral Filter
I'm working on a nice approximation for the Bilateral Filter.
I have a working code which runs pretty fast yet still I think much can be improved.
The code (C Code,...
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Using multi-threading efficiently with million GET requests
Disclaimer: The following question is not related to any malicious activity. Only performance testing we are doing.
I am working on querying an internal server with lots of requests (~20 million).
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Converting Reverse Polish to Infix Notation in Java
I am trying to solve a programming challange that involves converting reverse polish notation to infix notation. For example: 1 3 + 2 4 5 - + / would be: ((1+3)/(2+(4-5))) My solution so far does work,...
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Swift - Finding longest binary gap of a given integer
I recently had the chance to try Codility's algorithm training, and the very first one in the list is finding the longest binary gap of a given integer.
I tried to implement this in Swift, and after ...
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Seating Students (partitioning sort of)
The goal of this code is to seat students in a classroom based on a
single test score. We want students to be evenly distributed across
the class such that every student is positioned next to the ...
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Pandas: missing value imputation
I want to find a more efficient solution to the following problem:
My dataset is about online games. Each player may have multiple plays (rows in the df). Each play has its corresponding timestamp. ...
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