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Commit e7bb4e6

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feat(js): add modular solution and documentation for hard challenge 8 - Regular Expression Matching with DP
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# Regular Expression Matching with Dynamic Programming
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## English
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Regular expression matching is a fundamental problem in computer science, with applications in text processing, compilers, and search engines. Dynamic programming provides an efficient way to handle complex patterns with branching and repetition.
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This challenge involves designing a regular expression matching engine that supports special characters like '.' and '*', using dynamic programming techniques.
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### Relevant Code Snippet
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```javascript
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class RegexMatcher {
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constructor(text, pattern) {
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this.text = text;
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this.pattern = pattern;
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this.dp = Array.from({ length: text.length + 1 }, () =>
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new Array(pattern.length + 1).fill(false)
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);
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}
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isMatch() {
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this.dp[0][0] = true;
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for (let j = 2; j <= this.pattern.length; j++) {
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if (this.pattern[j - 1] === '*') {
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this.dp[0][j] = this.dp[0][j - 2];
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}
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}
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const matches = (i, j) => {
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if (
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this.pattern[j - 1] === '.' ||
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this.pattern[j - 1] === this.text[i - 1]
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) {
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return this.dp[i - 1][j - 1];
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}
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if (this.pattern[j - 1] === '*') {
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const zero = this.dp[i][j - 2];
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const oneOrMore =
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(this.pattern[j - 2] === '.' ||
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this.pattern[j - 2] === this.text[i - 1]) &&
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this.dp[i - 1][j];
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return zero || oneOrMore;
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}
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return false;
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};
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for (let i = 1; i <= this.text.length; i++) {
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for (let j = 1; j <= this.pattern.length; j++) {
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this.dp[i][j] = matches(i, j);
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}
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}
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return this.dp[this.text.length][this.pattern.length];
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}
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}
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```
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### History
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Regular expression matching has been extensively studied in computer science and is widely used in text processing, compilers, and search engines.
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---
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## Español
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Coincidencia de Expresiones Regulares con Programación Dinámica
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La coincidencia de expresiones regulares es un problema fundamental en ciencias de la computación, con aplicaciones en procesamiento de texto, compiladores y motores de búsqueda. La programación dinámica proporciona una forma eficiente de manejar patrones complejos con branching y repetición.
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Este reto consiste en diseñar un motor de coincidencia de expresiones regulares que soporte caracteres especiales como '.' y '*', usando técnicas de programación dinámica.
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### Fragmento de Código Relevante
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```javascript
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class RegexMatcher {
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constructor(text, pattern) {
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this.text = text;
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this.pattern = pattern;
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this.dp = Array.from({ length: text.length + 1 }, () =>
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new Array(pattern.length + 1).fill(false)
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);
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}
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isMatch() {
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this.dp[0][0] = true;
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for (let j = 2; j <= this.pattern.length; j++) {
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if (this.pattern[j - 1] === '*') {
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this.dp[0][j] = this.dp[0][j - 2];
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}
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}
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const matches = (i, j) => {
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if (
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this.pattern[j - 1] === '.' ||
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this.pattern[j - 1] === this.text[i - 1]
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) {
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return this.dp[i - 1][j - 1];
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}
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if (this.pattern[j - 1] === '*') {
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const zero = this.dp[i][j - 2];
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const oneOrMore =
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(this.pattern[j - 2] === '.' ||
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this.pattern[j - 2] === this.text[i - 1]) &&
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this.dp[i - 1][j];
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return zero || oneOrMore;
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}
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return false;
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};
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for (let i = 1; i <= this.text.length; i++) {
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for (let j = 1; j <= this.pattern.length; j++) {
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this.dp[i][j] = matches(i, j);
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}
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}
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return this.dp[this.text.length][this.pattern.length];
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}
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}
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```
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### Historia
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La coincidencia de expresiones regulares ha sido ampliamente estudiada en ciencias de la computación y es ampliamente utilizada en procesamiento de texto, compiladores y motores de búsqueda.
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// RegexMatcher.js - Regular Expression Matching using Dynamic Programming in JavaScript
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class RegexMatcher {
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constructor(text, pattern) {
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this.text = text;
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this.pattern = pattern;
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this.dp = Array.from({ length: text.length + 1 }, () =>
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new Array(pattern.length + 1).fill(false)
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);
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}
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isMatch() {
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this.dp[0][0] = true;
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for (let j = 2; j <= this.pattern.length; j++) {
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if (this.pattern[j - 1] === "*") {
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this.dp[0][j] = this.dp[0][j - 2];
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}
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}
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const matches = (i, j) => {
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if (
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this.pattern[j - 1] === "." ||
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this.pattern[j - 1] === this.text[i - 1]
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) {
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return this.dp[i - 1][j - 1];
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}
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if (this.pattern[j - 1] === "*") {
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const zero = this.dp[i][j - 2];
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const oneOrMore =
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(this.pattern[j - 2] === "." ||
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this.pattern[j - 2] === this.text[i - 1]) &&
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this.dp[i - 1][j];
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return zero || oneOrMore;
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}
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return false;
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};
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for (let i = 1; i <= this.text.length; i++) {
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for (let j = 1; j <= this.pattern.length; j++) {
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this.dp[i][j] = matches(i, j);
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}
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}
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return this.dp[this.text.length][this.pattern.length];
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}
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}
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export default RegexMatcher;
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/*
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Challenge:
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Design a regular expression matching engine that supports special characters like '.' and '*', using dynamic programming techniques to efficiently handle branching and backtracking.
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This solution follows DRY principles and is implemented in JavaScript.
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*/
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import RegexMatcher from "./RegexMatcher.js";
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function main() {
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const text = "aab";
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const pattern = "c*a*b";
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const matcher = new RegexMatcher(text, pattern);
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const result = matcher.isMatch();
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console.log(
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`Does the text "${text}" match the pattern "${pattern}"?`,
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result
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);
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}
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main();

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