PwC interview prep

DSAMedium

How many subsequences of [1, 2, 3, 4] have elements adding up to 5?

1. 1
2. 3
3. 4
4. 2

This topic is named in a candidate’s interview report: Acceleration Center associate interview, 2022, on GeeksforGeeks.

JavaMedium

What does this print?

public class Main {
    static int f() {
        try {
            throw new RuntimeException("x");
        } catch (RuntimeException e) {
            System.out.print("catch ");
            return 1;
        } finally {
            System.out.print("finally ");
        }
    }

    public static void main(String[] args) {
        System.out.print(f());
    }
}

1. catch 1
2. catch finally 1
3. finally catch 1
4. catch finally

This topic is named in a candidate’s interview report: Associate on-campus interview, 2020, on GeeksforGeeks.

DBMS and SQLHard

What does this query return for each employee?

SELECT name, dept, salary,
       AVG(salary) OVER (PARTITION BY dept) AS dept_avg
FROM emp;

1. One row per department with its average salary
2. An error: AVG needs GROUP BY
3. Every employee row, plus the average salary of all employees in the company
4. Every employee row, plus the average salary of that employee's own department

This topic is named in a candidate’s interview report: Associate on-campus interview, 2020, on GeeksforGeeks.

DBMS and SQLMedium

What does adding an index on a column usually do?

1. Speeds up queries that search or sort on that column, at the cost of extra storage and slower inserts and updates
2. Speeds up every query on the table, with no cost
3. Prevents duplicate values in the column
4. Compresses the table to save space

This topic is named in a candidate’s interview report: Acceleration Center associate interview, 2022, on GeeksforGeeks.

DBMS and SQLEasy

What is a trigger in SQL?

1. A query that runs on a schedule, such as every night
2. Code the database runs automatically when a chosen event, such as an INSERT, UPDATE or DELETE on a table, happens
3. A constraint that stops NULL values
4. Another name for a stored procedure the user calls by hand

This topic is named in a candidate’s interview report: Acceleration Center associate interview, 2022, on GeeksforGeeks.

DBMS and SQLMedium

Which query lists the salary values that are shared by more than one employee?

1. SELECT DISTINCT salary FROM emp;
2. SELECT salary FROM emp WHERE COUNT(salary) > 1;
3. SELECT salary FROM emp GROUP BY salary HAVING COUNT(*) > 1;
4. SELECT salary FROM emp ORDER BY salary;

This topic is named in a candidate’s interview report: Acceleration Center associate interview, 2022, on GeeksforGeeks.

Computer networksMedium

How does an intrusion prevention system (IPS) differ from an intrusion detection system (IDS)?

1. An IPS sits in the traffic path and can block malicious traffic; an IDS watches a copy of the traffic and raises alerts
2. An IDS blocks traffic; an IPS only logs it
3. They are the same thing
4. An IPS encrypts traffic and an IDS decrypts it

This topic is named in a candidate’s interview report: Cybersecurity consultant on-campus interview, 2021, on GeeksforGeeks.

AptitudeHard

There are 10 stacks of 10 coins. Every coin weighs 10 g except in one stack, where every coin weighs 11 g. With one reading of a digital scale, how do you find that stack?

1. Weigh one coin from each stack together
2. Weigh stacks 1 to 5 against stacks 6 to 10
3. It cannot be done in one weighing
4. Take 1 coin from stack 1, 2 from stack 2, and so on up to 10 from stack 10, weigh them all: the grams over 550 give the stack number

This topic is named in a candidate’s interview report: Associate on-campus interview, 2020, on GeeksforGeeks.