Problem Overview

You are implementing an employee management system with four progressive levels of complexity. Each level builds on the previous one, adding new features for tracking employee time, promotions, and compensation.

This is a typical online assessment (OA) problem where levels unlock sequentially. The starter code for Level 1 is provided - you'll extend it for subsequent levels.

Level Summary

• Level 1: Add employees and track clock in/out

• Level 2: Query total office time and find top K employees by office time

• Level 3: Promotions with deferred activation and salary queries for time periods

• Level 4: Double salary time periods

Important Notes

• Timestamps are in milliseconds

• Design data structures that can be extended for future levels

• The starter code provides basic structure - extend it as needed

Level 1: Basic Employee Operations

Implement basic employee management functionality including adding employees and tracking when they enter and leave the office.

Operations

add_employee(name, position, hourly_salary)

• Add a new employee to the system

• Store name, position, and hourly salary rate

clock_in(name, timestamp)

• Record when employee leaves the office

• Store clock in/out pair for later calculations

` ems = EmployeeManagementSystem() ems.add_employee("Alice", "Engineer", 50.0) ems.clock_in("Alice", 1000) ems.clock_out("Alice", 5000)

Alice worked from timestamp 1000 to 5000 (4000 time units)

`

• Store employee information

• Maintain records of clock in/out times

• Handle multiple clock sessions per employee

• Can employees clock in multiple times without clocking out?

• What happens if clock_out is called without a matching clock_in?

• Should we validate timestamps (ensure clock_out is greater than clock_in)?

Support querying employee office time statistics and ranking employees by time spent in the office.

• Find the top K employees who have spent the most time in the office

• Return list of employee names

• Ranked by total office time (descending)

` ems.add_employee("Bob", "Manager", 75.0) ems.clock_in("Bob", 0) ems.clock_out("Bob", 3000) ems.clock_in("Bob", 5000) ems.clock_out("Bob", 9000)

total = ems.get_total_office_time("Bob")

Returns: 7000 (3000 + 4000)

top = ems.top_k_employees_by_office_time(1)

Returns: ["Bob"] if Bob has most office time

`

• Efficiently calculate cumulative office time

• Sort employees by time spent in office

• Handle edge case when K is greater than number of employees

Implement promotion functionality with deferred activation and support querying total compensation for any time period.

announce_promotion(name, new_position, new_salary)

• Announce a promotion for an employee

• Promotion does NOT take effect immediately

• Promotion takes effect on the next clock in after announcement

• New salary applies to all hours worked after promotion takes effect

• Calculate total salary earned during time period [start, end]

• Formula: Total Salary = Clock Time × Hourly Rate

• Must account for different hourly rates if promotions occurred during the period

• Only count time when employee was actually in the office (clocked in)

` ems.add_employee("Alice", "Engineer", 50.0) ems.clock_in("Alice", 1000) ems.clock_out("Alice", 3000)

Alice works 2000 units at 50/unit = 100000

ems.announce_promotion("Alice", "Senior Engineer", 75.0) ems.clock_in("Alice", 5000) # Promotion takes effect now ems.clock_out("Alice", 8000)

Alice works 3000 units at 75/unit = 225000

salary = ems.query_salary_for_period("Alice", 0, 10000)

Returns: 325000 (100000 + 225000)

`

• Store pending promotions

• Apply promotion on next clock in

• Track hourly rate for each clock session

• Calculate salary considering overlapping time periods and rate changes

Store the hourly rate with each clock record to handle salary changes between sessions:

employee.clock_records.append((clock_in, clock_out, hourly_salary_at_time))

Support designating certain time periods as double salary periods, where employees earn twice their normal hourly rate.

• Hours worked during double salary periods earn double the normal rate

• Handle cases where work sessions overlap with double salary periods

• Handle cases where promotions and double salary periods interact

` ems.add_employee("Charlie", "Engineer", 50.0) ems.define_double_salary_period(2000, 4000)

ems.clock_in("Charlie", 1000) ems.clock_out("Charlie", 5000)

salary = ems.query_salary_for_period("Charlie", 1000, 5000)

Breakdown:

1000-2000: normal (1000 × 50 = 50000)

2000-4000: double (2000 × 50 × 2 = 200000)

4000-5000: normal (1000 × 50 = 50000)

Total: 300000

`

• Store multiple double salary periods

• Segment work periods at double salary boundaries

• Calculate each segment separately with correct multiplier

• Handle overlapping double salary periods