Beginner Exercism • javascript

Queen Attack

Challenge Overview

Given the position of two queens on a chess board, indicate whether or not they are positioned so that they can attack each other.

Source: Exercism javascript/queen-attack

💡 View Solution

export class QueenAttack {
  constructor({ white, black } = {}) {
    this.white = white || [0, 3];
    this.black = black || [7, 3];

    if (this.white[0] === this.black[0] && this.white[1] === this.black[1]) {
      throw new Error('Queens cannot share the same space');
    }
    
    [...this.white, ...this.black].forEach(coord => {
      if (coord < 0 || coord > 7) {
        throw new Error('Queen must be placed on the board');
      }
    });
  }

  toString() {
    let board = Array.from({ length: 8 }, () => Array(8).fill('_'));
    board[this.white[0]][this.white[1]] = 'W';
    board[this.black[0]][this.black[1]] = 'B';
    return board.map(row => row.join(' ')).join('\n');
  }

  get canAttack() {
    const [wr, wc] = this.white;
    const [br, bc] = this.black;

    return wr === br || wc === bc || Math.abs(wr - br) === Math.abs(wc - bc);
  }
}