01204212/nearby search

From 01204212-59

You are given a locations of players, monsters, and the radius. Output the total number of monsters seen by any players.

Input format:

• First line: n m r (where n is the number of players, m is the number of monsters, and r is a radius)
• The next n lines, for each line the co-ordinate for each player: x y
• The next m lines, for each line the co-ordinate for each monster: x y

Test data: Download here

A few answers:

• n100: 5
• n1000: 311
• n5000: 7803
• n10000: 31072