/constructor first null/no links on list yet /public void insertfirst(int iddouble dd/make new link link newlink new link(iddd)newlink next first/it points to old first link first newlink/now first points to this /public link find(int key/find link with given key /(assumes non-empty listlink current first/start at 'firstwhile(current idata !key/while no matchif(current next =null/if end of listreturn null/didn' find it else /not end of listcurrent current next/go to next link return current/found it /public link delete(int key/delete link with given key /(assumes non-empty listlink current first/search for link link previous firstwhile(current idata !keyif(current next =nullreturn null/didn' find it else previous current/go to next link current current next/found it if(current =first/if first linkfirst first next/change first else /otherwiseprevious next current next/bypass it return current