This is a personal project! I don´t use snippets, but I know that a lot of people use them, then I will try to do a little collection of some code snippets that you will be able to use in the contests.
Competitive Programming C# snippets of code ready to import and use in Visual Studio
If you are using C# and Visual Studio 2012, you will be able to copy inside your VSfolder:
..\VC#\Snippets\1033\Visual C#\
And inside here you can copy all the snippets, or you can import them.
Inside VS012, Tools -> Code Snippets Manager and Import.
Still working on them…
Thanks for use