diff options
| -rw-r--r-- | 2024/day_03_part_2.f90 | 83 |
1 files changed, 83 insertions, 0 deletions
diff --git a/2024/day_03_part_2.f90 b/2024/day_03_part_2.f90 new file mode 100644 index 0000000..4b3af7f --- /dev/null +++ b/2024/day_03_part_2.f90 @@ -0,0 +1,83 @@ +program day_03_part_2 + implicit none + logical :: find_a, is_dont + integer ::io, ios, a, b, state, res + character(len=1) :: c + character(len=10) :: buffer + character(len=4) :: mul_cmd = 'mul(' + character(len=7) :: dont_cmd = "don't()" + character(len=4) :: do_cmd = 'do()' + + res = 0 + open(newunit=io, file='./day_03_input.txt', status='old', action='read', access='stream') + state = 0 ! 0 = find command, 1 = find number, 2 = calculate + find_a = .true. + is_dont = .false. + buffer = '' + do + read(io, iostat=ios) c + if (ios /= 0) exit + select case(state) + case (0) ! find command + buffer = trim(buffer) // c + if(is_dont) then + if (trim(buffer) == do_cmd) then + state = 0 + buffer = '' + is_dont = .false. + else if (trim(buffer) /= do_cmd(1:len(trim(buffer)))) then + state = 0 + buffer = '' + end if + else + if (trim(buffer) == dont_cmd) then + state = 0 + buffer = '' + is_dont = .true. + else if(trim(buffer) == mul_cmd) then + state = 1 + buffer = '' + else if(trim(buffer) /= mul_cmd(1:len(trim(buffer))) .and. trim(buffer) /= dont_cmd(1:len(trim(buffer)))) then + state = 0 + buffer = '' + end if + end if + case (1) ! find digits + select case (iachar(c)) + case (48:57) ! 0-9 + buffer = trim(buffer) // c + case (44) ! , + if (find_a .and. len(trim(buffer)) > 0) then + read(buffer, *) a + buffer = '' + find_a = .false. + else + state = 0 ! invalid + find_a = .true. + buffer = '' + end if + case (41) ! ) + if(.not. find_a .and. len(trim(buffer)) > 0) then + read(buffer, *) b + state = 2 + find_a = .true. + buffer = '' + else + state = 0 + find_a = .true. + buffer = '' + end if + case default + state = 0 + find_a = .true. + buffer = '' + end select + end select + if(state == 2) then + res = res + (a * b) + state = 0 + buffer = '' + end if + end do + print*, res +end program day_03_part_2 |