Any method to solve auto-suggestive dropdown method using keys

lang:java

I have been trying to automate auto suggestive dropdowns, but if I give the both the text and keys in single line, it is not giving the site to load options. Keeping this thing in mind, I went ahead with thread sleep method and waited for the suggestions to load, but the cursor is coming out of the web element and keys operations are not being performed. please help me with this....

import org.openqa.selenium.By;
import org.openqa.selenium.Keys;
import org.openqa.selenium.WebDriver;
import org.openqa.selenium.WebElement;
import org.openqa.selenium.chrome.ChromeDriver;

public class suggestivedropdown {

	public static void main(String[] args) throws InterruptedException {
		// TODO Auto-generated method stub
		System.setProperty("webdriver.chrome.driver","C:\\Users\\teddy\\Downloads\\chromedriver.exe");
		WebDriver driver = new ChromeDriver();
		driver.get("https://www.makemytrip.com/");
	//	driver.findElement(By.xpath("//input[@id='fromCity']")).clear(); this is if it contains default option
	  WebElement source=driver.findElement(By.xpath("//input[@id='fromCity']"));
	  source.sendKeys("HYD");
	Thread.sleep(3000);
	source.sendKeys(Keys.ARROW_DOWN);
	source.sendKeys(Keys.ENTER);
	  WebElement destination=driver.findElement(By.xpath("//input[@id='toCity']"));
       destination.sendKeys("MUM");
       Thread.sleep(3000);
       destination.sendKeys(Keys.ARROW_DOWN);
       destination.sendKeys(Keys.ENTER);

You shouldn't use hard coded sleeps in the code . If you are facing synchronization issue use waits to avoid issues, Refer below solution :

    driver.get("https://www.makemytrip.com/");
    WebDriverWait wait = new WebDriverWait(driver, 30);

    wait.until(ExpectedConditions.elementToBeClickable(By.xpath("//input[@id='fromCity']"))).sendKeys("Hyd");
    wait.until(ExpectedConditions.elementToBeClickable(By.xpath("//p[contains(text(),'Hyderabad, India')]"))).click();

    wait.until(ExpectedConditions.elementToBeClickable(By.xpath("//input[@id='toCity']"))).sendKeys("Mumbai");
    wait.until(ExpectedConditions.elementToBeClickable(By.xpath("//p[contains(text(),'Mumbai, India')]"))).click();