高频题（0）
1. Determine high-value leads from limited information
Given a table with columns 'date', 'user_id', 'lead_id', 'listing_price', and considering that one user can submit multiple leads, how would you determine which are the high-value leads using only the information provided in the table?
2. Write a SQL query to pick the most recent lead submission of each user
Given a table with columns 'date', 'user_id', 'lead_id', 'listing_price', write a SQL query to select the most recent lead submission for each user.
