diff options
| -rw-r--r-- | 2024/day_07_part_2.f90 | 68 |
1 files changed, 68 insertions, 0 deletions
diff --git a/2024/day_07_part_2.f90 b/2024/day_07_part_2.f90 new file mode 100644 index 0000000..a2bc12c --- /dev/null +++ b/2024/day_07_part_2.f90 @@ -0,0 +1,68 @@ +module day_07_part_2_utils + use iso_fortran_env, only: int64 + implicit none +contains + recursive function test_values(arr, target, next_idx, current_value) result(pass) + implicit none + integer(kind=int64), intent(in) :: target, current_value, arr(:) + integer, intent(in) :: next_idx + character(len=20) :: str_1, str_2, concat_str + integer(kind=int64) :: concat_value + logical :: pass + + if(next_idx > size(arr)) then + pass = current_value == target + return + end if + + write(str_1, '(I0)') current_value + write(str_2, '(I0)') arr(next_idx) + concat_str = trim(str_1) // trim(str_2) + read(concat_str, '(I20)') concat_value + + pass = test_values(arr, target, next_idx + 1, current_value + arr(next_idx)) .or. & + test_values(arr, target, next_idx + 1, current_value * arr(next_idx)) .or. & + test_values(arr, target, next_idx + 1, concat_value) + end function test_values + logical function is_calibrated(arr, target) + implicit none + integer(kind=int64), intent(in) :: target, arr(:) + + is_calibrated = test_values(arr, target, 2, arr(1)) + end function is_calibrated +end module day_07_part_2_utils +program day_07_part_2 + use iso_fortran_env, only: int64 + use day_07_part_2_utils + implicit none + integer(kind=int64) :: test_number, res + integer(kind=int64), allocatable:: work(:) + integer :: io, ios, idx, i, ct + character(len=200) :: line, work_line + logical :: pass + res = 0 + open(newunit=io, file='./day_07_input.txt', status='old', action='read') + do + read(io, '(a)', iostat=ios) line + if (ios /= 0) exit + idx = index(line, ':') + if (idx > 0) then + read(line(1:idx-1), *) test_number + ct = 0 + work_line = trim(line(idx+1:len(trim(line)))) + do i = 1 , len(trim(work_line)) + if(work_line(i:i) == ' ') then + ct = ct + 1 + end if + end do + allocate(work(ct)) + read(work_line, *) work(:) + end if + pass = is_calibrated(work, test_number) + if(pass) then + res = res + test_number + end if + deallocate(work) + end do + print*, "Result: ", res +end program day_07_part_2 |