305_user_logs_sessions_events

305. Пользовательские логи

📋 Problem Description

This problem involves analyzing user activity logs stored in log.csv. Each line represents a single event with the format:

timestamp,user_id,event_type,event_parameter

🎯 Tasks

1. Session Counting

• Definition: A session is a sequence of events by the same user
• Session End Rule: Session ends after 30+ minutes of inactivity
• Goal: Count sessions that started on 2020-04-19

2. Most Active Video Day

• Video Event: event_type = 2 and event_parameter = "video"
• Goal: Find the day with the maximum number of unique users who watched videos
• Return: The count of unique users (not the date)

3. Most Active 5-Minute Interval

• Goal: Find the 5-minute interval [time, time + 5 minutes) with the most events
• Tie-breaker: If multiple intervals have the same count, return the latest one
• Return: Start time in format YYYY-MM-DD_hh:mm:ss

🔧 Solution Approach

Session Counting Algorithm

1. Group events by user_id and sort by timestamp
2. For each user, identify session start points:
   • First event starts a session
   • Any event after a 30+ minute gap starts a new session
3. Count sessions that started on the target date

Video Day Analysis

1. Filter events with type=2 and parameter="video"
2. Group by date and collect unique user_ids per day
3. Return the maximum count of unique users

Active Interval Detection

1. Sort all timestamps chronologically
2. Use sliding window approach to check each possible 5-minute interval
3. Count events in each window and track the best (preferring later times for ties)

📊 Output Format

<session_count> <max_unique_users> <interval_start_time>

Example: 67890 111 2020-01-31_10:09:12

🚀 Usage

python solution.py

Prerequisites:

• log.csv file in the same directory
• Python 3.6+ with datetime module

🏷️ Tags

• Data Analysis
• Log Processing
• Time Series Analysis
• Sliding Window Algorithm
• Session Management

📈 Complexity

• Time: O(n log n) due to sorting operations
• Space: O(n) for storing user activities and timestamps

🔗 Links

• Original Problem
• More Solutions