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✨ feat: implement '@algorithm.ts/manacher'
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Diff for: ‎README.md

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[@algorithm.ts/isap][] | ISAP algorithm. #MaxFlow, #NetworkFlow.
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[@algorithm.ts/knuth-shuffle][] | Knuth-Shuffle algorithm.
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[@algorithm.ts/lower-bound][] | Find the index of first elements which greater or equals than the target element.
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[@algorithm.ts/manacher][] | The manacher algorithm for solving palindrome string problems.
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[@algorithm.ts/mcmf][] | MCMF algorithm. #MinCostMaxFlow, #NetworkFlow.
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[@algorithm.ts/priority-queue][] | Priority Queue (heap).
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[@algorithm.ts/sliding-window][] | Sliding window algorithm.
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[@algorithm.ts/isap]: ./packages/isap
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[@algorithm.ts/knuth-shuffle]: ./packages/knuth-shuffle
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[@algorithm.ts/lower-bound]: ./packages/lower-bound
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[@algorithm.ts/manacher]: ./packages/manacher
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[@algorithm.ts/mcmf]: ./packages/mcmf
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[@algorithm.ts/priority-queue]: ./packages/priority-queue
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[@algorithm.ts/sliding-window]: ./packages/sliding-window

Diff for: ‎packages/manacher/README.md

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<header>
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<h1 align="center">
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<a href="https://github.com/guanghechen/algorithm.ts/tree/main/packages/manacher#readme">@algorithm.ts/manacher</a>
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</h1>
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<div align="center">
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<a href="https://www.npmjs.com/package/@algorithm.ts/manacher">
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<img
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alt="Npm Version"
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src="https://img.shields.io/npm/v/@algorithm.ts/manacher.svg"
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/>
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</a>
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<a href="https://www.npmjs.com/package/@algorithm.ts/manacher">
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<img
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alt="Npm Download"
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src="https://img.shields.io/npm/dm/@algorithm.ts/manacher.svg"
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/>
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</a>
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<a href="https://www.npmjs.com/package/@algorithm.ts/manacher">
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<img
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alt="Npm License"
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src="https://img.shields.io/npm/l/@algorithm.ts/manacher.svg"
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/>
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</a>
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<a href="#install">
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<img
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alt="Module Formats: cjs, esm"
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src="https://img.shields.io/badge/module_formats-cjs%2C%20esm-green.svg"
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/>
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</a>
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<a href="https://github.com/nodejs/node">
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<img
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alt="Node.js Version"
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src="https://img.shields.io/node/v/@algorithm.ts/manacher"
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/>
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</a>
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<a href="https://github.com/facebook/jest">
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<img
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alt="Tested with Jest"
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src="https://img.shields.io/badge/tested_with-jest-9c465e.svg"
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/>
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</a>
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<a href="https://github.com/prettier/prettier">
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<img
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alt="Code Style: prettier"
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src="https://img.shields.io/badge/code_style-prettier-ff69b4.svg?style=flat-square"
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/>
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</a>
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</div>
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</header>
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<br/>
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A typescript implementation of the **manacher** algorithm.
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Manacher is a linear time algorithm for listing all the palindromes that appear
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at the start of a given string.
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If you are interested in this algorithm, you can check [here][manacher].
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## Install
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* npm
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```bash
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npm install --save @algorithm.ts/manacher
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```
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* yarn
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```bash
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yarn add @algorithm.ts/manacher
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```
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* deno
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```typescript
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import manacher from 'https://raw.githubusercontent.com/guanghechen/algorithm.ts/main/packages/manacher/src/index.ts'
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```
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## Usage
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* A solution of https://leetcode.com/problems/palindrome-partitioning-ii/
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```typescript
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import manacher from '@algorithm.ts/manacher'
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export function minCut(s: string): number {
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const N: number = s.length
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const f: number[] = manacher(s)
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const dp: Uint32Array = new Uint32Array(N)
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for (let i = 1; i < N; ++i) {
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let answer: number = i < f[i] * 2 ? 0 : dp[i - 1] + 1
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if (answer > 0) {
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for (let k = 1; k < i; ++k) {
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if (i - k < f[i + k] * 2) {
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answer = Math.min(answer, dp[k - 1] + 1)
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}
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}
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}
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dp[i] = answer
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}
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return dp[N - 1]
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}
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```
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## Related
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* [最长回文子串 Manacher 算法][manacher]
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[homepage]: https://github.com/guanghechen/algorithm.ts/tree/main/packages/manacher#readme
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[manacher]: https://me.guanghechen.com/post/algorithm/string/manacher/

Diff for: ‎packages/manacher/__test__/manacher.spec.ts

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import manacher from '../src'
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test('manacher', function () {
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const data: Array<{
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input: Parameters<typeof solution1>
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answer: ReturnType<typeof solution1>
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}> = [
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{
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input: ['aab'],
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answer: 1,
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},
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{
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input: ['a'],
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answer: 0,
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},
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{
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input: ['ab'],
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answer: 1,
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},
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{
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input: ['abaacaada'],
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answer: 2,
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},
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{
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input: [
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'aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaabbaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa',
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],
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answer: 1,
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},
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]
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for (const { input, answer } of data) {
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expect(solution1(...input)).toEqual(answer)
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}
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})
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/**
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* @see https://leetcode.com/problems/palindrome-partitioning-ii
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*/
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function solution1(text: string): number {
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const N: number = text.length
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const f: number[] = manacher(text)
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const dp: Uint32Array = new Uint32Array(N)
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for (let i = 1; i < N; ++i) {
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let answer: number = i < f[i] * 2 ? 0 : dp[i - 1] + 1
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if (answer > 0) {
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for (let k = 1; k < i; ++k) {
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if (i - k < f[i + k] * 2) {
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answer = Math.min(answer, dp[k - 1] + 1)
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}
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}
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}
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dp[i] = answer
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}
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return dp[N - 1]
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}

Diff for: ‎packages/manacher/package.json

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{
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"name": "@algorithm.ts/manacher",
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"version": "1.0.18",
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"description": "The manacher algorithm for solving palindrome string problems",
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"author": {
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"name": "guanghechen",
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"url": "https://github.com/guanghechen/"
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},
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"repository": {
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"type": "git",
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"url": "https://github.com/guanghechen/algorithm.ts.git",
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"directory": "packages/manacher"
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},
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"homepage": "https://github.com/guanghechen/algorithm.ts/tree/main/packages/manacher#readme",
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"keywords": [
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"algorithm",
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"manacher",
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"palindrome"
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],
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"main": "lib/cjs/index.js",
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"module": "lib/esm/index.js",
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"types": "lib/types/index.d.ts",
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"source": "src/index.ts",
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"license": "MIT",
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"engines": {
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"node": ">= 14.15.0"
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},
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"files": [
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"lib/",
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"!lib/**/*.js.map",
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"!lib/**/*.d.ts.map",
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"package.json",
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"CHANGELOG.md",
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"LICENSE",
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"README.md"
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],
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"scripts": {
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"build": "cross-env NODE_ENV=production rollup -c ../../rollup.config.js",
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"prebuild": "rimraf lib/ && tsc -p tsconfig.src.json --emitDeclarationOnly",
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"prepublishOnly": "cross-env ROLLUP_SHOULD_SOURCEMAP=false yarn build",
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"test": "cross-env TS_NODE_FILES=true jest --config ../../jest.config.js --rootDir ."
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}
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}

Diff for: ‎packages/manacher/src/index.ts

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/**
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* Find the longest palindrome length centered at each position in the given
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* text string within the complexity of $O(N)$.
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*
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* Note: len is an array with a length of $2N-1$, which represents the radius
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* of the palindrome:
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*
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* - len[2i] is equal to the radius of the longest palindrome centered at
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* the position (i, i)
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*
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* - len[2i+1] is equal to the radius of the longest palindrome centered at
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* the position (i, i+1)
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*
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* ## Examples
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*
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* 'abbab'
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*
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* ==>
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*
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* len[3] = 2 // abba
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* len[6] = 2 // bab
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*
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* @param text
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* @param len
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* @param N
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*
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* @see https://me.guanghechen.com/post/algorithm/string/manacher/
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*/
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export function manacher(text: string): number[] {
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const N = text.length
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const _size = N * 2 - 1
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const len: number[] = new Array(_size)
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len[0] = 1
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for (let i = 1, j = 0; i < _size; ++i) {
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const p: number = i >> 1
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const q: number = i - p
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const r: number = ((j + 1) >> 1) + len[j] - 1
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let L = r < q ? 0 : Math.min(r - q + 1, len[(j << 1) - i])
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while (p > L - 1 && q + L < N && text[p - L] === text[q + L]) L += 1
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len[i] = L
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// Update j
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if (q + L - 1 > r) j = i
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}
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return len
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}
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export default manacher

Diff for: ‎packages/manacher/tsconfig.json

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{
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"extends": "../../tsconfig",
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"include": ["src", "script", "__test__"]
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}

Diff for: ‎packages/manacher/tsconfig.src.json

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{
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"extends": "../../tsconfig.settings",
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"compilerOptions": {
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"declarationDir": "lib/types",
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"rootDir": "src"
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},
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"include": ["src"]
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}

Diff for: ‎tsconfig.json

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"@algorithm.ts/isap": ["packages/isap/src"],
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"@algorithm.ts/knuth-shuffle": ["packages/knuth-shuffle/src"],
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"@algorithm.ts/lower-bound": ["packages/lower-bound/src"],
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"@algorithm.ts/manacher": ["packages/manacher/src"],
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"@algorithm.ts/mcmf": ["packages/mcmf/src"],
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"@algorithm.ts/priority-queue": ["packages/priority-queue/src"],
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"@algorithm.ts/sliding-window": ["packages/sliding-window/src"],

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