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import {    PrefixTreeInsert,} from "../design-add-and-search-words-data-structure/PrefixTreeInsert.ts";import { PrefixTree } from "../implement-trie-prefix-tree/PrefixTree.ts";
function findWords(board: string[][], words: string[]): string[] {    const ans = new Set(words);
    if (board.length === 1 && board[0].length === 1) {        return words.filter(            (word) => word.length === 1 && word === board[0][0],        );    }    if (words.length === 0) return [];    words.forEach((w) => {        if (w.length === 0) {            ans.delete(w);        }    });    const row = board.length;    if (!row) {        return [];    }    const col = board[0].length;    if (!col) {        return [];    }
    const all_chars = new Set(board.flat());    words.forEach((word) => {        if (Array.prototype.some.call(word, (c) => !all_chars.has(c))) {            ans.delete(word);        }    });
    words = Array.from(ans);
    const result = new Set<string>();
    const root = PrefixTree();    for (const word of ans) {        PrefixTreeInsert(root, word);    }    const visited: boolean[][] = Array.from(board).map((a) =>        Array.from(a).map(() => false)    );    for (let i = 0; i < row; i++) {        for (let j = 0; j < col; j++) {            if (root.children.has(board[i][j])) {                dfs(i, j, visited, board, row, col, "", root, result);            }        }    }
    return Array.from(result);}const directions: Array<[number, number]> = [    [0, 1],    [1, 0],    [0, -1],    [-1, 0],];
function dfs(    i: number,    j: number,    visited: boolean[][],    board: string[][],    row: number,    col: number,    prefix: string,    now: PrefixTree,    result: Set<string>,) {    const node = now.children.get(board[i][j]);    if (!node) return;    if (node?.isEnd) {        result.add(prefix + board[i][j]);        node.isEnd = false;    }    if (visited[i][j]) {        return;    }    visited[i][j] = true;    prefix += board[i][j];    now = node;    for (const [f, s] of directions) {        const x = i + f;        const y = j + s;        if (x >= 0 && y >= 0 && x < row && y < col && !visited[x][y]) {            dfs(x, y, visited, board, row, col, prefix, now, result);        }    }    visited[i][j] = false;    return false;}
export default findWords;