In　the　sub-7nm　technology　nodes,　as　the　mask　cost　for　printing　the　dense　via　layers　increases　dramatically　with　conventional　lithography　techniques,　triple　block　copolymer　(triple-BCP)　materials　for　directed　self-assembly　(DSA)　lithography　is　considered　as　a　promising　technology　to　reduce　the　mask　cost.　In　this　paper,　we　consider　triple-BCP　and　template　assignment　for　triple　patterning　lithography　with　DSA.　Firstly,　we　formulate　the　problem　as　a　maximum　weighted　independent　set　(MWIS)　problem,　and　then　use　the　integer　linear　programming　(ILP)　to　obtain　its　solution.　Furthermore,　to　gain　a　better　trade-off　between　runtime　and　solution　quality,　we　proposed　a　modification　of　the　Fiduccia-Mattheyses　heuristic　method　(MCFM)　to　efficiently　solve　the　MWIS　problem.　Experimental　results　verify　the　effectiveness　of　our　method,　and　indicate　that　adopting　three　different　BCP　materials　can　dramatically　reduce　conflict　numbers　compared　with　existing　works　using　double　BCP　materials.　©　2019　IEEE.