Write a program that receives some info from the console about people and their phone numbers.

You are free to choose the manner in which the data is entered; each entry should have just one name and one number (both of them strings). If you receive a name that already exists in the phonebook, simply update its number.

After filling this simple phonebook, upon receiving the command "search", your program should be able to perform a search of a contact by name and print her details in format "{name} -> {number}". In case the contact isn't found, print "Contact {name} does not exist." Examples:

Examples:

You will be given:

• An integer N representing the amount of elements to enqueue (add)
• An integer S representing the amount of elements to dequeue (remove/poll) from the queue
• An integer X, an element that you should check whether is present in the queue.

If it is print true on the console, if it’s not print the smallest element currently present in the queue. If the stack is empty print 0.

Examples:

For the 1st task (with 5 2 32...) comment: We have to push 5 elements. Then we pop 2 of them. Finally, we have to check whether 32 is present in the stack. Since it is we print true.

Use the Stack<Integer> class. Just put the input numbers in the stack and pop them.

Examples:

• 1 x - Push the element x into the stack.
• 2    - Delete the element present at the top of the stack.
• 3    - Print the maximum element in the stack.

Input Format: The first line of input contains an integer, N. The next N lines each contain an above mentioned query. (It is guaranteed that each query is valid.)

Output Format: For each type 3 query, print the maximum element in the stack on a new line.

Constraints:
1 ≤ N ≤ 10⁵ 
1 ≤ x ≤ 10⁹
1 ≤ type ≤ 3

Here is an examples:

Can you please give me some examples of Map's usage in Java?

Thank you!

Thanks, John

For example I have 12 months and instead of getting this in the console:

• January
• February
• March
• April
• May
• June
• July
• August
• September
• October
• November
• December

I want to get this:

• December
• November
• October
• September
• August
• July
• June
• May
• April
• March
• February
• January

....in reverse order!

Here is my code:

public class MonthsNumber {
 
    public static void main(String[] args) {
 
        String[] monthsNumber = {"January", "February", "March", "April", "May", "June", "July", "August", "September", "October", "November", "December"};
 
        for (int i = 0; i < months.length; i++) {
            System.out.println(months);
        }
    }
}

What kind of shortcuts and live templates do you use in IntelliJ Idea: https://www.jetbrains.com/idea/?

Can you please share some - so I can work faster :-) Thanks

For example I have this code:

ArrayList<Integer> n = new ArrayList<>();
n.add(4);
n.add(5);
n.add(434);
n.add((int) 9.5);
 
System.out.println(n);

The output in this case is:

But I want to print it without the brackets - only the numbers: 4, 5, 434, 9

• What is regex and how can I use it in Java (and IntelliJ Idea)?
• Are there site which explains regex's use?
• Can you please share?

Thanks, Jolie