function memoize(fn) {
 
}

// Пример использования
function slowFunction(num) {
  // Симуляция тяжелых вычислений
  for (let i = 0; i < 1e9; i++) {}
  return num * 2;
}

const memoizedSlowFunction = memoize(slowFunction);

console.log(memoizedSlowFunction(5)); // Вычисляет и кэширует результат
console.log(memoizedSlowFunction(5)); // Возвращает закэшированный результат

var foo = 1; 
function bar() { 
    if (!foo) { 
        var foo = 10; 
    } 
    console.log(foo); 
} 
bar();

function foo() { 
    var x = 1; 
    if (x) { 
        (function () { 
            var x = 2; 
        }()); 
    } 
console.log(x)
}

function f() {
  console.log( this );
}

let user = {
  g: f.bind(null)
};

user.g();

function greetWaitAndAgain() {
  console.log(`Hello, ${this.name}!`)
  setTimeout(() => {
    console.log(`Hello again, ${this.name}!`)
  })
}

const user = { name: 'Alex' }

user.greetWaitAndAgain = greetWaitAndAgain;
user.greetWaitAndAgain()

function f() {
    this.x = 5;
    console.log(this);
}
var o = new f();
console.log(o.x); 

Array.prototype.myFilter = function(callback) {

};

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

const filteredArr = arr.myFilter(x => x > 2);
console.log(filteredArr); // [3, 4, 5]

function searchAllAnagramsInString(str, substr) {

}

// Пример использования:
console.log(searchAllAnagramsInString("cbaebabacd", "abc")); // [0, 6]

function findMaxDayWithClients(bookings) {
  // Реализуйте логику поиска самого загруженного дня
}

findMaxDayWithClients([[1, 5], [2, 4], [3, 6]]); // 3
// В день 3 отель был максимально загружен (3 клиента)

function customPromiseAll(promises) {
  
}

// Пример использования
const promise1 = Promise.resolve(3);
const promise2 = Promise.resolve(42);
const promise3 = new Promise((resolve) => setTimeout(resolve, 100, 'foo'));

customPromiseAll([promise1, promise2, promise3])
  .then(results => console.log(results)) // [3, 42, 'foo']
  .catch(error => console.error(error));

const transactions = [
  { userID: "user1", amount: 200, date: "2023-01-01" },
  { userID: "user2", amount: 500, date: "2023-01-02" },
  { userID: "user1", amount: 300, date: "2023-01-03" },
  { userID: "user3", amount: 400, date: "2023-01-01" },
  { userID: "user2", amount: 150, date: "2023-01-04" },
  { userID: "user3", amount: 250, date: "2023-01-02" },
  { userID: "user4", amount: 100, date: "2023-01-01" }
];

function topThreeUsersByTotalAmount(transactions) {
 //тут
}

getJson('json/1')
  .then(json => {
    if(json.key) {
      return getJson('json/2')
    }
    throw new Error('No key')
  })
  .then(json => {
    return json.key2
  })
  .catch(e => {
    console.log(e)
  })

function fetchWithRetries(retriesCount, ...fetchArgs) {
    /* */
}

function reduce(array, callback, initial) {
    let acc = initial
    
    for(let i = 0; i < array.length; i++) {
        acc = callback(acc, array[i], i)
    }
    
    return acc
}

compress([1, 4, 3, 2]) // '1-4'

compress([1, 4]) //'1, 4'

class Store {
    /*  */
}
  
  const store = new Store()
  
  const firstSubscriber = (data) => console.log('first', data)
  const secondSubscriber = (data) => console.log('second', data)
  
  store.subscribe(firstSubscriber)
  store.subscribe(secondSubscriber)
  
  store.data = {newKey: 'newString'}
  
  /** CONSOLE
   * first {newKey: 'newString'}
   * second {newKey: 'newString'}
   */
  
  store.unsubsribe(firstSubscriber)
  
    /** CONSOLE
   * second {newKey: 'newString'}
   */
}

setTimeout(() => {
  console.log('setTimeout')
})

const promise = new Promise((resolve, reject) => {
  console.log(1);
  setTimeout(() => {
    console.log("timerStart");
    resolve("success");
    console.log("timerEnd");
  }, 0);

  Promise.resolve().then(() => {
    console.log('resolve')
  })
  console.log(2);
});

promise.then((res) => {
  console.log(res);
});

console.log(4);

setTimeout(function timeout() {
   console.log('Таймаут 1');
}, 0);

let p = new Promise(function(resolve, reject) {
   console.log('Создание промиса');

   setTimeout(function timeout() {
     console.log('Таймаут 2');
   }, 0);

   resolve();
});

p.then(function(){
   console.log('Обработка промиса');
});

console.log('Конец скрипта');

const myPromise = (delay) => new Promise((res, rej) => { setTimeout(res, delay) })

setTimeout(() => console.log('in setTimeout1'), 1000);

myPromise(1000).then(res => console.log('in Promise 1'));

setTimeout(() => console.log('in setTimeout2'), 100);

myPromise(2000).then(res => console.log('in Promise 2'));

setTimeout(() => console.log('in setTimeout3'), 2000);

myPromise(1000).then(res => console.log('in Promise 3'));

setTimeout(() => console.log('in setTimeout4'), 1000);

myPromise(5000).then(res => console.log('in Promise '));

console.log(1); 

setTimeout(() => console.log(2));

Promise.resolve().then(() => console.log(3));

Promise.resolve().then(() => setTimeout(() => console.log(4)));

Promise.resolve().then(() => console.log(5));

setTimeout(() => Promise.resolve().then(() => console.log(6)));

console.log(7);

console.log('start');

const promise1 = Promise.resolve().then(() => {
    console.log('promise1');
    const timer1 = setTimeout(() => {
        console.log('timer1')
        const promise2 = Promise.resolve().then(() => {
            console.log('promise2');
            const timer2 = setTimeout(() => {
                console.log('timer2')
            }, 0)
        })
    }, 0);
});

const timer3 = setTimeout(() => {
    console.log('timer3');
    const promise3 = new Promise(resolve => {
        setTimeout(() => {
            console.log('promise3');
            resolve();
        }, 0);
    }).then(() => {
        console.log('promise3 then');
    })
}, 0);

async function asyncFunction() {
    console.log('async start');
    await new Promise(resolve => setTimeout(resolve, 0));
    console.log('async middle');
    await Promise.resolve().then(() => console.log('async promise'));
    console.log('async end');
}

asyncFunction();

console.log('end');