Let there be a polygon with n vertices. What is the maximum number of edges you can draw between them without making a triangle (3 vertices are connected to each other)?
这题还挺简单,他要我写出一个general formula for n vertices。答案是(n/2)^2 if n is even, (n-1/2)^2+n/2+1/2 if n is odd。
然后另外一个问题是
Let's say you toss a coin 1000 times, and you win if you get 10 heads