All Questions
Tagged with comparative-review performance
148
questions
3
votes
2
answers
69
views
Reading a file into lines (benchmarking getline() vs mmap_memchr() vs mmap_getline() vs fread())
This is a follow-up to: Reading a file into lines with mmap vs getline.
The actual names of the functions are not ...
- 9,462
7
votes
1
answer
232
views
Reading a file into lines with mmap vs getline
I required a function to read a file into lines for a text editor, and ended up with two routines. One uses getline(), and the other uses ...
- 9,462
3
votes
1
answer
92
views
Simple C++ event loop - static vs dynamic dispatch performance
I have two extremely simple toy implementations of an event loop, and would like to understand the performance differences between them.
First impl - events with a virtual 'handle' method - dynamic ...
- 33
1
vote
0
answers
129
views
Making Robert Tarjan's offline LCA algorithm run (much) faster (Java)
I have produced this GitHub repository that compares the performance of:
Robert Tarjan's off-line lowest common ancestors algorithm,
An improvement of the above algorithm.
Typical demo program ...
- 28.9k
3
votes
1
answer
80
views
calculating the percentage of distribution of ids per Loc for each country
Which of the two queries is theoretically better and why?
I would like to understand why query 2 takes longer although there is no relevant information in the Execution Plan.
I'm querying a Presto ...
- 71
2
votes
1
answer
161
views
C/C++ hash looking in flat database compared to PHP
I have a hash table which I would like to query as fast as possible.
The hash table is stored this way :
When I query a hash, I extract first 4 characters then use it to find the file. For instance a ...
- 41
1
vote
2
answers
114
views
Circular list vs. doubly-linked list: which is faster?
In this post, I will compare performance of a circular list and a conventional list with head/tail -references:
...
- 28.9k
5
votes
2
answers
664
views
Recursively calculating powers by squaring
Consider the following function that implements optimised O(log n) exponentiation by squaring:
...
- 229
2
votes
4
answers
1k
views
Calculate the median value of combining two sorted lists
I have solved a leetcode problem (Median of Two Sorted Arrays), and I came up with two solutions.
Solution 1
...
- 45
2
votes
1
answer
153
views
LeetCode#494 target sum (dart is slower than python)
I'm trying to solve a LeetCode problem target-sum, in two languages: Python & Dart. The difference of time taken is shocking for me"
Python took ~70ms while Dart took ~900ms !! Why does Dart ...
- 123
2
votes
1
answer
158
views
Card game simulations, with a multithreaded version slower than the single-threaded one
I'm new to rust and I'm trying to build a card game simulation to find all of the best actions with all possible hands. This requires a lot of simulations and my first 3 million are already taking a ...
- 21
0
votes
1
answer
129
views
Find longest "binary gap" [closed]
I'm doing a few challenges and I found this one on Codility:
A binary gap within a positive integer N is any maximal sequence of
consecutive zeros that is surrounded by ones at both ends in the
...
- 101
0
votes
1
answer
71
views
2 ConvertToBase3 methods with great disparity of execution time
I have two methods to do the same thing: convert a number to ternary.
...
- 109
4
votes
3
answers
411
views
Pairwise Euclidean distance search algorithm
x and y are two-dimensional arrays with dimensions (AxN) and (BxN), i.e. they have the same number of columns.
I need to get a matrix of Euclidean distances between each pair of rows from x and y.
I ...
1
vote
0
answers
47
views
Graph stored as adjacency list or as endpoints and intervals
I tried speeding up my Graph class, so I removed the Node class and Edge class, and decided to use arrays and ArrayLists. My 2 implementations seem very similar, ...
- 111