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| -rw-r--r-- | 2024/day_05.f90 | 112 |
1 files changed, 112 insertions, 0 deletions
diff --git a/2024/day_05.f90 b/2024/day_05.f90 new file mode 100644 index 0000000..2c1d26a --- /dev/null +++ b/2024/day_05.f90 @@ -0,0 +1,112 @@ +module day_05_utils +contains + subroutine append_to_integer_array(arr, val) + integer, allocatable, intent(inout) :: arr(:) + integer, intent(in) :: val + integer, allocatable :: temp(:) + if(.not. allocated(arr)) then + ERROR STOP 'Array not allocated' + end if + allocate(temp(size(arr) + 1)) + temp(1:size(arr)) = arr + temp(size(arr) + 1) = val + call move_alloc(temp, arr) + end subroutine append_to_integer_array +end module day_05_utils +program day_05 + use day_05_utils + implicit none + integer :: io, ios, idx, a, b, ct, i, j, res + integer, allocatable :: left(:), right(:), print_list(:), work(:) + character(len=100) ::line + logical :: found + + open(newunit=io, file='./day_05_input.txt', status='old', action='read') + res = 0 + do + read(io, '(a)', iostat=ios) line + if(ios /= 0) exit !eof + idx = index(line, '|') + if(idx > 0) then ! rules + read(line(1:idx-1), *) a + read(line(idx+1:), *) b + if(.not. allocated(left)) then + allocate(left(1)) + left(1) = a + else + call append_to_integer_array(left, a) + end if + if(.not. allocated(right)) then + allocate(right(1)) + right(1) = b + else + call append_to_integer_array(right, b) + end if + end if + idx = index(line, ',') + if (idx > 0 ) then ! print_list + ct = 1 + do i = 1 , len_trim(line) + if(line(i:i) == ',') then + ct = ct + 1 + end if + end do + allocate(print_list(ct)) + read(line, *) print_list + found = .false. + do i = 1, size(print_list) + if(i+1 < size(print_list)) then ! if we can check forward + do j = 1, size(right) ! find value in right and save left to work + if (print_list(i) == right(j)) then + if(.not. allocated(work)) then + allocate(work(1)) + work(1) = left(j) + else + call append_to_integer_array(work, left(j)) + end if + end if + end do + do j = 1, size(work) + if(any(print_list(i+1:size(print_list)) == work(j))) then + found = .true. + exit + end if + end do + deallocate(work) + end if + if(.not. found) then ! if we are still valid lets keep going + if(i-1 > 0) then ! if we can check backwards + do j = 1, size(left) ! find value in left and save left to work + if (print_list(i) == left(j)) then + if(.not. allocated(work)) then + allocate(work(1)) + work(1) = right(j) + else + call append_to_integer_array(work, right(j)) + end if + end if + end do + do j = 1, size(work) + if(any(print_list(1:i-1) == work(j))) then + found = .true. + exit + end if + end do + deallocate(work) + end if + else + exit + end if + end do + if (.not. found) then + res = res + print_list((size(print_list) + 1)/2) + end if + + deallocate(print_list) + end if + end do + + deallocate(left) + deallocate(right) + print*, "Result ", res +end program day_05 |