【旧代码】fortran中的指针实现链表的代码

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program link implicit none type node character(20) name integer id integer score type(node),pointer ::next end type integer,parameter::num=3 type(node),pointer ::students call init_all(students,num) call show_all(students) print*,"now,we add a student" call add_node(students) call show_all(students) print*,"now,we delete the student" call del_node(students) call show_all(students) contains subroutine add_node(pos) type(node),pointer ::pos,tmp allocate(tmp) tmp%name="abc" tmp%id=1 tmp%score=100 print*,"please input name,id,end score of one students" read*,tmp%name,tmp%id,tmp%score if(associated(pos%next)) then tmp%next=>pos%next pos%next=>tmp else nullify(tmp%next) pos%next=>tmp end if end subroutine subroutine del_node(pos) type(node),pointer ::pos,next next=>pos%next if(associated(next%next)) then pos%next=>next%next deallocate(next) else nullify(pos%next) deallocate(next) end if end subroutine subroutine show_all(pos) type(node),pointer ::pos,tmp integer ::cnt cnt=1 print*,"all students are:" tmp=>pos do while(associated(tmp)) print*,cnt,"th ",tmp%name,tmp%id,tmp%score tmp=>tmp%next cnt=cnt+1 end do end subroutine subroutine init_all(pos,num) type(node),pointer ::pos,tmp,walk integer num integer i allocate(tmp) nullify(tmp%next) call add_node(tmp) pos=>tmp%next deallocate(tmp) walk=>pos do i=1,num-1 call add_node(walk) walk=>walk%next end do end subroutine end program link