프로그래머스 - 교점에 별 만들기

part52. 교점에 별 만들기

js ver 1.0

function solution(line) {
    const set = new Set();
    let maxX = -Infinity, maxY = -Infinity, minX = Infinity, minY = Infinity;

    for (let i = 0; i < line.length; i++) {
        for (let j = i + 1; j < line.length; j++) {
            const [a, b, c] = line[i];
            const [d, e, f] = line[j];
            const determinant = a * e - d * b;

            if (determinant == 0) continue;

            const x = (b * f - e * c) / determinant;
            const y = (d * c - a * f) / determinant;

            if (Number.isInteger(x) && Number.isInteger(y)) {
                set.add(`${x},${y}`);
                maxX = Math.max(maxX, x);
                maxY = Math.max(maxY, y);
                minX = Math.min(minX, x);
                minY = Math.min(minY, y);
            }
        }
    }

    const meet = [...set].map(point => {
        const [x, y] = point.split(',').map(Number);
        return [x - minX, maxY - y];
    });

    const board = Array.from({ length: maxY - minY + 1 }, () => Array(maxX - minX + 1).fill('.'));

    meet.forEach(([x, y]) => {
        board[y][x] = '*';
    });

    return board.map(row => row.join(''));
}

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