AdventOfCode2021/Day4/Bingo.ts

import { readLines } from "https://deno.land/std@0.177.1/io/read_lines.ts";

class BingoBoard {
    board: string[][];
    hits: boolean[][];

    constructor(board: string[][]) {
        this.board = board;
        this.hits = [[false,false,false,false,false],
                     [false,false,false,false,false],
                     [false,false,false,false,false],
                     [false,false,false,false,false],
                     [false,false,false,false,false]];
    }

    checkRow(j:number): boolean {
        for (let i = 0; i < this.board.length; i++) {
            if (!this.hits[i][j]) {
                return false;
            }
        }
        return true;
    }

    checkColumn(j:number): boolean {
        for (let i = 0; i < this.board[j].length; i++) {
            if (!this.hits[j][i]) {
                return false;
            }
        }
        return true;
    }

    hit(num:string) {
        for (let i = 0; i < this.board.length; i++) {
            for (let j = 0; j < this.board[i].length; j++) {
                if (this.board[i][j] == num) {
                    this.hits[i][j] = true;
                    return [i,j];
                }
            }
        }
        return [-1,-1];
    }

    hitAndSolve(num:string): boolean {
        const [x,y] = this.hit(num);
        if (x == -1 || y == -1) {
            return false
        }
        return this.checkRow(y) || this.checkColumn(x);
    }

    sumOfUnmarkedNumbers(): number {
        let sum = 0;
        for (let i = 0; i < this.board.length; i++) {
            for (let j = 0; j < this.board[i].length; j++) {
                if (!this.hits[i][j]) {
                    sum += +this.board[i][j];
                }
            }
        }
        return sum;
    }
}

async function Part1() {
    const file = await Deno.open("./Day4/input.txt");

    const lines = readLines(file);
    const numbers: string[] = (await lines.next()).value.split(",");
    const boards: BingoBoard[] = [];

    let currBoard: string[][] = []; 

    for await (const line of lines) {
        if (line == "") {
            continue;
        }
        currBoard.push(line.split(" ").filter(x => x != ""));
        if (currBoard.length == 5) {
            boards.push(new BingoBoard(currBoard));
            currBoard = [];
        }
    }

    for (const num of numbers) {
        for (const b of boards) {
            if (b.hitAndSolve(num)) {
                return +num * b.sumOfUnmarkedNumbers();
            }
        }
    }
    return 0;
}

async function Part2() {
    const file = await Deno.open("./Day4/input.txt");

    const lines = readLines(file);
    const numbers: string[] = (await lines.next()).value.split(",");
    const boards: BingoBoard[] = [];

    let currBoard: string[][] = []; 

    for await (const line of lines) {
        if (line == "") {
            continue;
        }
        currBoard.push(line.split(" ").filter(x => x != ""));
        if (currBoard.length == 5) {
            boards.push(new BingoBoard(currBoard));
            currBoard = [];
        }
    }
    
    const isDeadBoard: boolean[] = new Array(boards.length);
    isDeadBoard.fill(false);
    let deadBoards = boards.length;

    for (const num of numbers) {
        for (const i in boards) {
            if (isDeadBoard[i]) {
                continue
            }
            const b = boards[+i];
            if (b.hitAndSolve(num)) {
                if (deadBoards == 1) {
                    return +num * b.sumOfUnmarkedNumbers();
                } else {
                    isDeadBoard[i] = true;
                    deadBoards--;
                }
            }
        }
    }
    return 0;
}

console.log("Part1: " + await Part1());
console.log("Part1: " + await Part2());