https://github.com/yudai/golcs

Go Longest Common Subsequence
https://github.com/yudai/golcs

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Go Longest Common Subsequence

• Host: GitHub
• URL: https://github.com/yudai/golcs
• Owner: yudai
• License: mit
• Created: 2015-04-05T05:15:15.000Z (over 10 years ago)
• Default Branch: master
• Last Pushed: 2021-10-07T06:43:35.000Z (about 4 years ago)
• Last Synced: 2024-12-09T19:38:36.615Z (10 months ago)
• Language: Go
• Homepage:
• Size: 201 KB
• Stars: 21
• Watchers: 3
• Forks: 5
• Open Issues: 3
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

          
# Go Longest Common Subsequence (LCS)

[![GoDoc](https://godoc.org/github.com/yudai/golcs?status.svg)][godoc]

[![MIT License](http://img.shields.io/badge/license-MIT-blue.svg)][license]

[godoc]: https://godoc.org/github.com/yudai/golcs

[license]: https://github.com/yudai/golcs/blob/master/LICENSE

A package to calculate [LCS](http://en.wikipedia.org/wiki/Longest_common_subsequence_problem) of slices.

## Usage

```sh

go get github.com/yudai/golcs

```

```go

import " github.com/yudai/golcs"

left = []interface{}{1, 2, 5, 3, 1, 1, 5, 8, 3}

right = []interface{}{1, 2, 3, 3, 4, 4, 5, 1, 6}

lcs := golcs.New(left, right)

lcs.Values()     // LCS values       => []interface{}{1, 2, 5, 1}

lcs.IndexPairs() // Matched indices  => [{Left: 0, Right: 0}, {Left: 1, Right: 1}, {Left: 2, Right: 6}, {Left: 4, Right: 7}]

lcs.Length()     // Matched length   => 4

lcs.Table()      // Memo table

```

All the methods of `Lcs` cache their return values. For example, the memo table is calculated only once and reused when `Values()`, `Length()` and other methods are called.

## FAQ

### How can I give `[]byte` values to `Lcs()` as its arguments?

As `[]interface{}` is incompatible with `[]othertype` like `[]byte`, you need to create a `[]interface{}` slice and copy the values in your `[]byte` slice into it. Unfortunately, Go doesn't provide any mesure to cast a slice into `[]interface{}` with zero cost. Your copy costs O(n).

```go

leftBytes := []byte("TGAGTA")

left = make([]interface{}, len(leftBytes))

for i, v := range leftBytes {

	left[i] = v

}

rightBytes := []byte("GATA")

right = make([]interface{}, len(rightBytes))

for i, v := range rightBytes {

	right[i] = v

}

lcs.New(left, right)

```

## LICENSE

The MIT license (See `LICENSE` for detail)