8주차 Discussion

[chloe-codes1]

📢 책을 읽으면서 궁금한 점들을 자유롭게 적고 대답해 주세요

8주차 진행 방식

1. 진도: 3.1 - 3.2 읽어오고 정리 & 의견 나누기
2. 문제 풀이: 3.1, 3.5, 3.7, 3.9, 3.10, 3.11 문제 풀고, Github 에 올리기 (총 6문제)

[bigsaigon333]

3.1

function make_accumulator(initialValue) {
  return (value) => (initialValue += value);
}

[bigsaigon333]

https://www.oreilly.com/library/view/javascript-the-definitive/9781449393854/ch04s11.html

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Assignment

[bigsaigon333]

3.5

// x1 <= x2, y1 <= y2 가 성립한다고 가정
function estimate_integral(P, x1, x2, y1, y2, trials) {
  function experiment() {
    const rx = random_in_range(x1, x2);
    const ry = random_in_range(y1, y2);
    return P(rx, ry);
  }

  return (x2 - x1) * (y2 - y1) * monte_carlo(trials, experiment);
}

function monte_carlo(trials, experiment) {
  function iter(trials_remaining, trials_passed) {
    return trials_remaining === 0
      ? trials_passed / trials
      : experiment()
        ? iter(trials_remaining - 1, trials_passed + 1)
        : iter(trials_remaining - 1, trials_passed);
  }

  return iter(trials, 0);
}

function random_in_range(low, high) {
  const range = high - low;
  return low + Math.random() * range;
}

const pi = estimate_integral(
  (x, y) => x ** 2 + y ** 2 <= 1,
  -1,
  1,
  -1,
  1,
  10000,
);

console.log(pi);

[bigsaigon333]

3.7

function make_joint(account, original_password, new_password) {
  return (password, m) =>
    password !== new_password
      ? error("Incorrect password")
      : account(original_password, m);
}

function make_account(balance, password) {
  function withdraw(amount) {
    if (balance >= amount) {
      balance = balance - amount;
      return balance;
    } else {
      return "Insufficient funds";
    }
  }

  function deposit(amount) {
    balance = balance + amount;
    return balance;
  }

  function dispatch(user_password, m) {
    return user_password !== password
      ? error("Incorrect password")
      : m === "withdraw"
        ? withdraw
        : m === "deposit"
          ? deposit
          : error(m, "unknown request -- make_account");
  }

  return dispatch;
}

function error(value, message) {
  throw Error(`${value}: ${message}`);
}

[sunhpark42]

몬테카를로를 이용하여 최대공약수가 1일 확률(두 수가 서로소일 확률)

• 두수가 서로소일 확률: https://rayc20.tistory.com/90
• 책 원문 6*pi^2 -> 6/pi^2 입니다. 분수임