【旧代码】fortran中的指针实现链表的代码

我不喜欢fortran，

奇怪的词法规则（竟然不用空格分开token），

io操作竟然是语言的一部分（这种非本质的东西像C那样用库来扩展多好）

。。。

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

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

我很少讨厌某种技术，坦诚的说，关于fortran，是有其他因素参合进来了。