oh yeah,  nearly 1000 submits, i dont remember

so I get a conclusion:

I use veronoi diagram algorithm ,it will have precision error.

if you sort coordinates by x,  you will get WA on test 17,if you sort it by y,you will get WA on test 21..

so I combine them together, do sort them by x,then sort them by y, and compare the minimum distance, it'll get AC..

so I get a conclusion:

I use veronoi diagram algorithm ,it will have precision error.

if you sort coordinates by x,  you will get WA on test 17,if you sort it by y,you will get WA on test 21..

so I combine them together, do sort them by x,then sort them by y, and compare the minimum distance, it'll get AC..

gz. It is called "lexicographical sorting".