dpss 0.16.0

Solves subset sum problem and returns a set of decomposed integers. It also can match corresponding numbers from two vectors and be used for Account reconciliation.

Subset Sum(dpss)

This is a Rust implementation that calculates subset sum problem using dynamic programming. It solves subset sum problem and returns a set of decomposed integers. It also can match corresponding numbers from two vectors and be used for Account reconciliation.

Any feedback is welcome!

There are three ways to use this program.

• CLI
• Rust
• Python

Here is an out of the box example you can run now in google colab. https://colab.research.google.com/github/europeanplaice/subset_sum/blob/main/python/python_subset_sum.ipynb

And it has three methods.

• find_subset
  • It finds a subset from an array.
• find_subset_fast_only_positive
  • It finds a subset from an array. It can't accept negative values but relatively faster.
• Sequence Matcher
  • It finds subset sum relationships with two arrays.

dpss is short for dynamic programming subset sum.

Links

Name	URL
github	https://github.com/europeanplaice/subset_sum
crates.io	https://crates.io/crates/subset_sum
docs.rs	https://docs.rs/subset_sum/latest/dpss/
pypi	https://pypi.org/project/dpss/

CLI

Installation

Binary files are provided on the Releases page. When you download one of these, please add it to your PATH manually.

Usage

Subset sum

First, you need to prepare a text file containing a set of integers like this

1
2
-3
4
5

and save it at any place.

Second, call subset_sum with the path of the text file and the target sum.

Example

Call subset_sum.exe num_set.txt 3 3
The executable's name subset_sum.exe would be different from your choice. Change this example along with your environment. The second argument is the target sum. The third argument is the maximum length of the combination.

In this example, the output is
[[2, 1], [4, -3, 2], [5, -3, 1]]

Sequence Matcher

arr1.txt

1980
2980
3500
4000
1050

arr2.txt

1950
2900
30
80
3300
200
3980
1050
20

Call subset_sum.exe arr1.txt arr2.txt 100 100 10

In this example, the output is

[([1050], [1050]), ([1980], [30, 1950]), ([2980], [80, 2900]), ([3500], [200, 3300]), ([4000], [20, 3980])]
[([1050], [1050]), ([1980], [30, 1950]), ([2980], [80, 2900]), ([3500, 4000], [20, 200, 3300, 3980])]
[([1050], [1050]), ([1980], [30, 1950]), ([3500], [200, 3300]), ([2980, 4000], [20, 80, 2900, 3980])]
...

Use in Python

installation

pip install dpss

Usage

find_subset

import inspect
import dpss
help(dpss.find_subset)

>>> find_subset(arr, value, max_length, /)
>>>     Finds subsets sum of a target value. It can accept negative values.
>>>     # Arguments
>>>     * `arr` - An array.
>>>     * `value` - The value to the sum of the subset comes.
>>>     * `max_length` - The maximum length of combinations of the answer.

print(dpss.find_subset([1, -2, 3, 4, 5], 2, 3))

>>> [[4, -2], [3, -2, 1]]

find_subset_fast_only_positive

help(dpss.find_subset_fast_only_positive)

>>> find_subset_fast_only_positive(arr, value, max_length, /)
>>>    Finds subsets sum of a target value. It can't accept negative values but relatively faster.
>>>    # Arguments
>>>    * `arr` - An array.
>>>    * `value` - The value to the sum of the subset comes.
>>>    * `max_length` - The maximum length of combinations of the answer.

print(dpss.find_subset_fast_only_positive([1, 2, 3, 4, 5], 10, 4)) 

>>> [[4, 3, 2, 1], [5, 3, 2], [5, 4, 1]]

sequence_matcher

help(dpss.sequence_matcher)

>>> sequence_matcher(keys, targets, max_key_length, max_target_length /)
>>>     Finds the integers from two vectors that sum to the same value.
>>>     This method assumes that the two vectors have Many-to-Many relationships.
>>>     Each integer of the `keys` vector corresponds to the multiple integers of the `targets` vector.
>>>     With this method, we can find some combinations of the integers.
>>>     # Arguments
>>>     * `keys` - An array.
>>>     * `targets` - An array.
>>>     * `max_key_length` - An integer.
>>>     * `max_target_length` - An integer.
>>>     * `n_candidates` - An integer.

print(dpss.sequence_matcher([1980, 2980, 3500, 4000, 1050], [1950, 2900, 30, 80, 3300, 200, 3980, 1050, 20], 10, 10, 10))

>>> [([1050], [1050]), ([1980], [30, 1950]), ([2980], [80, 2900]), ([3500], [200, 3300]), ([4000], [20, 3980])]
>>> [([1050], [1050]), ([1980], [30, 1950]), ([2980], [80, 2900]), ([3500, 4000], [20, 200, 3300, 3980])]
>>> [([1050], [1050]), ([1980], [30, 1950]), ([3500], [200, 3300]), ([2980, 4000], [20, 80, 2900, 3980])]
...

Use in Rust

Please check https://crates.io/crates/subset_sum.

Cargo.toml

[dependencies]
dpss = { version = "(version)", package = "subset_sum" }

Find subset

main.rs

use dpss::dp::find_subset;

fn main() {
    let result = find_subset(&mut vec![1, 2, 3, 4, 5], 6, 3);
    println!("{:?}", result);
}

Output

[[3, 2, 1], [4, 2], [5, 1]]

Sequence Matcher

main.rs

use dpss::dp::sequence_matcher;

fn main() {
    let result = sequence_matcher(&mut vec![1980, 2980, 3500, 4000, 1050], &mut vec![1950, 2900, 30, 80, 3300, 200, 3980, 1050, 20], 10, 10, 10);
    println!("{:?}", result);
}

Output

[([1050], [1050]), ([1980], [30, 1950]), ([2980], [80, 2900]), ([3500], [200, 3300]), ([4000], [20, 3980])]
[([1050], [1050]), ([1980], [30, 1950]), ([2980], [80, 2900]), ([3500, 4000], [20, 200, 3300, 3980])]
[([1050], [1050]), ([1980], [30, 1950]), ([3500], [200, 3300]), ([2980, 4000], [20, 80, 2900, 3980])]
...