All Questions
Tagged with memory-optimization c++
47 questions
5
votes
1
answer
186
views
Memory-optimizing arduino code to be able to print all files from SD card
I started an Arduino project that could execute instructions from an SD card file on the screen. I managed to do it, but another problem appeared: I can't print all the files from the SD card to the ...
- 53
2
votes
1
answer
87
views
Generic container wrapper type with a default underlying buffer (2nd rev)
This is a revision of the previous question. I was told to ask an additional question with more context for the modified code to be reviewed.
The changes:
changed from ...
- 935
2
votes
1
answer
52
views
A collection based on a bitset to store a set of unique integers from a given range (rev. 3)
All right, let's do this one last time.
This is continuation of this review.
I applied most of the proposed changes, making interface of my container very close to that of ...
- 177
4
votes
1
answer
86
views
A collection based on a bitset to store a set of unique integers from a given range (rev. 2)
This is a continuation of this review. I applied most of the proposed changes.
These changes were focused mostly on decoupling the class from the rest of the program and making its interface more like ...
- 177
1
vote
1
answer
86
views
Collection that uses a bitset to store a huge set of unique integers from a given range (rev. 1)
Some (skippable) context:
I'm writing program that minimizes an arbitrary logical function. Such function takes an unsigned integer as an argument and returns either ...
- 177
1
vote
1
answer
203
views
Large file log parser with less memory footprint
This is a variation of an interesting problem I am currently dealing with. We have a large input file which is being continuously written (size: 10-20G). We need to write a log filter which reads ...
2
votes
2
answers
237
views
Generate the number of partitions of each integer
I've coded a program that calculates the number of partitions of n into at least two distinct parts, and is relatively quick too (about N^1.5 complexity). For input 30 000 it takes roughly 4 seconds. ...
- 21
5
votes
4
answers
2k
views
StringPool in C++
I wrote a simple string pool for my compiler in C++ and want to hear your thoughts on its design.
String pool has 2 functions: intern and ...
- 162
4
votes
3
answers
342
views
Optimize memory and disk usage for sequences of n-bit values
Motivation:
I am working with sequences of n-bit values coming from an ADC. I was initially using a std::vector<unsigned short> to store these values (12 bit ...
- 161
6
votes
2
answers
238
views
LeetCode 126: Word Ladder II -- Memory limit exceeded
I am trying to solve LC126, and got a memory limit exceeded for the following solution.
I've seen the answer here -- so I'll try to use Dijkstra as well, but I would like to understand why I get the ...
- 322
5
votes
3
answers
8k
views
Discussing approaches for converting Enum to String
I need to convert the ENUM to a respective string value for which I came up with two approaches and I'm trying to see why would a second approach be better than the first one if even in terms of ...
- 508
0
votes
1
answer
56
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How do I increase the memory efficiency of this longest substring implementation? (C++)
I'm practicing my coding on leetcode.
I implemented the following algorithm to solve the longest substring problem:
...
- 195
2
votes
3
answers
362
views
Fixed-size memory allocator
I've been trying to implement a simple Boost PMR allocator that has a fixed amount of memory. My first implementation (which can be found here) had undefined behavior and did not handle memory ...
- 31
0
votes
1
answer
65
views
Enter the randomly displayed letter console game
The below code segments compose a simple console game where the user is prompted to enter a randomly generated letter displayed in the console. It also saves and loads user data through a .txt file.
...
- 305
2
votes
1
answer
923
views
Alpha beta pruning with memorization (transposition tables) and bitboards (5x5 cumulative tic-tac-toe)
This is my first time trying solve a game using these techniques.
I've looked at pseudocode of alpha-beta pruning with transposition tables and rewritten it in c++.
...
- 258
2
votes
0
answers
109
views
Dynamic heterogeneous container
I want to have dynamic continuous block of memory for different types, that inherit from single base class. I've written structure for that purpose. I know I play with a fire here, but I would like to ...
- 21
3
votes
0
answers
195
views
0
votes
1
answer
73
views
Find a sum using just two different digits
The problem statement was pretty easy and I was able to run half of the test cases, but some of the test cases in the end gave me the error of memory limit reached. What can I do here to improve the ...
- 13
0
votes
1
answer
94
views
Simple C++ Dynamicly allocated Matrix with only one memory allocation [closed]
I was bothered with existing matrix allocation methods that take variable rows and columns, so I made a small class that only needs one memory allocation.
...
2
votes
1
answer
125
views
Preserving principle of locality while performing memory allocation
In order to implement an efficient AST visitor preserving the principle of locality, I implemented some reference counting mechanism in C++ with the following set of features:
All the newly allocated ...
- 113
3
votes
0
answers
165
views
Custom allocator for improved cache locality and fast iteration in C++
I am writing a custom allocator for my educational game engine project where I need to iterate through a collection of components(similar to Unity3D) every frame. There are game objects and every game ...
8
votes
2
answers
2k
views
hexdump(): A memory layout utility to help debugging / understanding / optimising of C++ memory model
EDIT: Refer this answer for improved solution with incorporated feedback and extended functionality. eg Automatically hexdump both parts of a stack/heap obj like <...
- 2,475
5
votes
1
answer
360
views
Optimizing away log function calls depending on global log level
I am a member of a university team designing a nanosatellite.
We decided to implement our own (more lite) logging library to use, instead of, say, Google's glog, <...
- 53
6
votes
2
answers
117
views
Program for activity selection exceeds time limit
I've been trying to solve this problem for some while and the solution I have come up with exceeds the lime limit by 1-3 ms and 2 out of 10 tests get a memory issue error. Why is that? This is the ...
- 159
1
vote
1
answer
118
views
Python's eval command in Arduino
I have made an equivalent of Python's "eval" command in Arduino (which in itself is quite a feat) but the part that decodes the output of it is not small enough to fit in another 30 functions since ...
- 113
6
votes
1
answer
210
views
Matrix class with space-optimized triangular (lower and upper) variants
I've written a class for square numerical matrices (of doubles, in this case), in C++11. Since I intend to use this class later ...
- 645
7
votes
2
answers
191
views
Prime number segmented sieve
I tried to solve the SPOJ prime number problem below. The code produced correct results, but Time limit exceeded and also memory need around 970M which is not efficient(?)
How can I optimize this ...
- 171
1
vote
2
answers
374
views
Codility's BinaryGap: Hardware-aware answer [closed]
This is a well-known question, which some others have posted about on this site.
Here's my first shot following a state machine approach:
...
6
votes
1
answer
777
views
Read CSV and use bidirectional BFS to find the shortest connections between actors
I have a really huge file¹ with 17 million records in it.
Here is a sample of the file:
Actor Movie
1,2
2,2
3,1
4,3
2,3
...
5
votes
1
answer
261
views
C++ class to compute similarity coefficients
I'm a complete beginner in C++. I wrote a class to compute similarity coefficients using Euclidean distance and Pearson coefficients on map data structure. I would ...
- 269
7
votes
2
answers
1k
views
The performance of the simulation for an ant's random walk on a 5x5 grid
I have written a simulation in order to solve the 280th problem in Project Euler, and the simulation basically repeat the given experiment 5m times, and for each experiment, writes the ExpNo - #...
- 171
1
vote
1
answer
143
views
Implement C++11 multipart sending without copying to a single buffer
I am working on a C++11 project and am migrating the underlying communications library used.
The original library allowed sending messages in multiple parts using a ...
- 83
3
votes
1
answer
1k
views
Counting subsets with sum not exceeding some limit
I am facing a variation of a subset sum problem. I have to count the number of subsets with sum less than or equal to some integer(limit). I think the optimal solution for this problem would be the ...
- 133
4
votes
3
answers
153
views
Associating a string with a derived class
I am using the following code to get a string that is associated with the class of an instance:
...
- 157
5
votes
1
answer
2k
views
C++11 : simple Tree implementation
I have created a C++11 implementation of a simple Tree for an online code challenge,
I'd like to know how to improve it and how to make my code use less memory :
...
- 121
0
votes
2
answers
198
views
Calculating shortest possible route between two given nodes
I recently came across this problem:
Heroes in Indian movies are capable of superhuman feats. For example,
they can jump between buildings, jump onto and from running trains,
catch bullets with ...
- 389
1
vote
2
answers
2k
views
Finding the longest palindrome from the given string
Recently I came across this problem which instructs me to find the longest substring which is a palindrome:
As we all know, a palindrome is a word that equals its reverse. Here
are some examples ...
- 389
3
votes
3
answers
493
views
Calculating number of unharmed leaves
I recently came across this problem that asks you to print the number of leaves not eaten by the caterpillars:
As we all know caterpillars love to eat leaves. Usually, a caterpillar
sits on leaf, ...
- 389
1
vote
1
answer
3k
views
Brute-force password cracker
I am trying to write a program to find a zip file's password. I know the password consists of only lower-case letters and it's length does not exceed 6 characters. I wanted to check the passwords of ...
- 13
7
votes
3
answers
9k
views
Rotation of elements in an array
We had to write a program that would perform rotation of elements in an array. The array size was entered by user, so it had to be in a sense, dynamic.
Rotation or Circular Shifting
Initial Array: <...
- 359
4
votes
2
answers
892
views
Memory Management Code
For a project I had to do a memory management problem without creating any custom classes or templates using the provided pool array and ...
- 43
4
votes
2
answers
2k
views
Binary file validity in C++/C++11: checking a binary header
I have some code for checking a binary header to see if a binary file is meant to be read by a certain program, and I could use some extra eyes to review it.
Assume the following ...
- 43
0
votes
1
answer
278
views
Simplest linked list in C++?
My context was basically to get my linked list implementation in C++ reviewed, since I wrote it from scratch and wanted to make it as simple as possible and learn from suggestions I get. I am trying ...
- 131
6
votes
2
answers
310
views
Extending Sieve of Eratosthenes beyond a billion - follow-up
Follow up form Extending Sieve of Eratosthenes beyond a billion
Taking suggestions from the comments on the previous post:
Updated Code: This takes about 22 seconds for MAX as \$10^9\$ to reach "...
- 823
32
votes
4
answers
3k
views
Extending Sieve of Eratosthenes beyond a billion
For MAX value of 1000000000 (\$10^9\$), it takes about 45 seconds to reach the line where it prints "done". How can I speed this ...
- 823
3
votes
3
answers
3k
views
Custom ArrayList class
Please review my custom ArrayList class I constructed from scratch and add any suggestions or constructive criticisms. The point of this template class is give the ...
6
votes
1
answer
259
views
Pool allocator for a scripting language parser
At the moment I'm writing a parser and interpreter for a custom scripting language, to learn more about the basic concepts involved and to get more familiar with tools like ...
- 17.2k