Thanks for the participation!
1863A - Channel was authored by Endagorion and prepared by irkstepanov
1863B - Split Sort was authored by Endagorion and prepared by ch_egor
1863C - MEX Repetition was authored by Endagorion and prepared by amethyst0
1863D - Two-Colored Dominoes was authored by Endagorion and prepared by AndreySergunin
1863E - Speedrun was authored by Endagorion and prepared by Golovanov399
1863F - Divide, XOR, and Conquer was authored by Endagorion and prepared by ch_egor
1863G - Swaps was authored by Endagorion and prepared by zemen
1863H - Goldberg Machine 3 was authored by Endagorion and prepared by Endagorion, irkstepanov
1863I - Redundant Routes was authored by Endagorion and prepared by Endagorion, irkstepanov