### ajecc's blog

By ajecc, history, 4 years ago, Can somebody explain how we can find the intersection of 2 line segments using only integer arithmetic (like this solution to a problem in a recent round 42626026)? I know how we can test if they intersect (with cross product), but I can't figure out how to find the exact point.

By ajecc, history, 5 years ago, Can someone help me with the following problem? : a farmer ties his goat outside of a building's fence, on the border of the fence. The whole area is filled with grass that the goat can eat. The fence is a convex polygon. Knowing the coordinates of the place the place the goat was tied to the fence, the length of the rope the goat is tied with and the coordinates of the polygon's vertices, calculate the surface of the place the goat can eat grass on, rounded to the nearest integer. (Number of vertices < 100 and they are given in anticlockwise order, coordinates in module < 10000, the coordinates are integers). By ajecc, history, 5 years ago, You are given a graph and a number k. Output the biggest set of nodes such as every node has at least k adjacent nodes that are also in the set. (The solution should have a better complexity than O(n^2), n = number of nodes) Thanks! By ajecc, history, 5 years ago, By ajecc, history, 5 years ago, 