function recursiveBinarySearch(arr, target, start = 0, end = arr.length - 1) {
  if (start > end) {
    return -1;
  }

  const mid = Math.floor((start + end) / 2);

  if (arr[mid] === target) {
    return mid;
  } else if (arr[mid] < target) {
    return recursiveBinarySearch(arr, target, mid + 1, end);
  } else {
    return recursiveBinarySearch(arr, target, start, mid - 1);
  }
}

const result = recursiveBinarySearch([1, 2, 3, 4, 5, 6, 7, 8, 9], 6);

console.log(result);

function recursiveReverseString(str) {
  return str === "" ? str : recursiveReverseString(str.substr(1)) + str[0];
}

const result = recursiveReverseString("hello");

console.log(result);

const obj = {
  0: 'a',
  1: 'b',
  length: 2
};

const result = Array.from(obj);

console.log(result);

function* generatorQuiz() {
  yield 1;
}

const generator = generatorQuiz();

setTimeout(() => console.log(generator.next().value), 0);

for (const value of generator) {
  console.log(value);
}

function recursivePascalTriangle(n, row = [1], triangle = []) {
  triangle.push(row);
  if (n === triangle.length) {
    return triangle;
  }
  const nextRow = [1];
  for (let i = 1; i < row.length; i++) {
    nextRow.push(row[i] + row[i - 1]);
  }
  nextRow.push(1);
  return recursivePascalTriangle(n, nextRow, triangle);
}

const result = recursivePascalTriangle(5);

console.log(result);

function recursiveNQueens(n) {
  const board = Array.from({ length: n }, () => Array.from({ length: n }, () => "."));

  const solutions = [];

  const isSafe = (row, col) => {
    for (let i = 0; i < row; i++) {
      if (board[i][col] === "Q") return false;
      const colOffset = row - i;
      if (col - colOffset >= 0 && board[i][col - colOffset] === "Q") return false;
      if (col + colOffset < n && board[i][col + colOffset] === "Q") return false;
    }
    return true;
  };

  const placeQueens = (row) => {
    if (row === n) {
      solutions.push(board.map(row => row.join("")));
      return;
    }
    for (let col = 0; col < n; col++) {
      if (isSafe(row, col)) {
        board[row][col] = "Q";
        placeQueens(row + 1);
        board[row][col] = ".";
      }
    }
  };

  placeQueens(0);

  return solutions;
}

const result = recursiveNQueens(4);

console.log(result);

const numbers = [1, 2, 3, 4, 5];

const sum = numbers.reduce((acc, curr) => {
  setTimeout(() => {
    acc += curr;
  }, 0);
  return acc;
}, 0);

console.log(sum);