aboutsummaryrefslogtreecommitdiff
path: root/2024/day_02.f90
blob: f60a9bb8da38eda0b4c2c89f2f105e5f9703a3ea (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
program day_02
  implicit none
  logical :: is_decrement, fail
  integer :: io, i,x, spaces, res
  integer, dimension(:), allocatable :: list
  character(len=100) :: line

  open(newunit=io, file='./day_02_input.txt', status='old', action='read')

  res = 0
  do i = 1, 1000 
    read(io, '(a)') line ! reading the line 
    spaces = 1 ! reset space count
    do x = 1, len(trim(line))
      ! counting spaces to see how big of an array we need to allocate
      if(iachar(line(x:x))== 32 ) then
        spaces = spaces+1 
      end if
    end do

    allocate(list(spaces))
    read(line, *) list !reading the ints into an array
    fail = .false.
      
    do x = 1, size(list) -1
      if (list(x) == list(x+1)) then 
        fail = .true.
        exit
      end if
      if(x == 1 .and. list(x) > list(x+1)) then
        is_decrement = .true.
      else if (x==1 .and. list(x) < list(x+1)) then
        is_decrement = .false.
      end if
      
      if(is_decrement)  then
        if (list(x) < list(x+1) .or. abs(list(x) - list(x+1)) > 3) then 
         fail = .true.
         exit 
        end if
      else
        if (list(x) >  list(x+1) .or. abs(list(x) - list(x+1)) > 3) then 
          fail = .true.
          exit 
        end if
      end if
    end do
    if (fail .eqv. .false.) then
     res = res + 1 
    endif
    deallocate(list)
  end do
  print*, res 
end program day_02