As　an　emerging　manufacture　technology,　block　copolymer　directed　self-assembly　(DSA)　is　promising　for　via　layer　fabrication.　Meanwhile,　redundant　via　insertion　is　considered　as　an　essential　step　for　yield　improvement.　For　better　reliability　and　manufacturability,　in　this　paper,　we　first　concurrently　consider　DSA　guiding　template　cost　assignment　with　multiple　redundant　via　and　dummy　via　insertion.　Firstly,　by　analyzing　the　structure　property　of　guiding　templates,　we　propose　a　building-block　based　solution　expression　to　discard　redundant　solutions.　Then,　honoring　the　compact　solution　expression,　we　construct　a　conflict　graph　with　dummy　via　insertion,　and　then　formulate　the　problem　to　an　integer　linear　programming　(ILP).　In　addition,　to　optimize　the　guiding　template　cost,　we　incorporate　it　into　the　objective　of　ILP　by　introducing　vertex　weight　and　edge　weight　in　conflict　graph.　To　make　a　good　trade-off　between　solution　quality　and　runtime,　we　relax　the　ILP　to　an　unconstrained　nonlinear　programming　(UNP).　Finally,　a　line　search　optimization　algorithm　is　proposed　to　solve　the　UNP.　Experimental　results　verify　the　effectiveness　of　our　new　solution　expression　and　the　efficiency　of　our　proposed　algorithm.　Specifically,　our　guiding　template　cost　optimization　method　can　save　18%　total　guiding　template　cost.