Another 2023 day 12 part 2 attempt

main
Petra 2023-12-16 14:17:48 +13:00
parent 8942f057f5
commit 2f8f875990
1 changed files with 153 additions and 116 deletions

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@ -6,6 +6,7 @@ program day12
character(200) :: fname character(200) :: fname
character(max_chars) :: fline character(max_chars) :: fline
character(max_chars) :: springs, spt character(max_chars) :: springs, spt
integer :: cache(1:20, 1:300)
integer :: tn_spr, n_springs integer :: tn_spr, n_springs
integer :: n_arguments integer :: n_arguments
integer :: n_repeats integer :: n_repeats
@ -73,7 +74,9 @@ program day12
num_wc = numstr(trim(springs), '?') num_wc = numstr(trim(springs), '?')
print *, "Length: ", n_springs print *, "Length: ", n_springs
print *, "Number of wildcards: ", num_wc print *, "Number of wildcards: ", num_wc
val = nvalid(springs, n_springs, specifiers, n_specifiers, .true.) print *, "Wildcard Combinations: ", 2**num_wc
cache = -1
val = nvalid(springs, n_springs, specifiers, n_specifiers)
print *, "Valid: ", val print *, "Valid: ", val
print * print *
total_valid = total_valid + val total_valid = total_valid + val
@ -85,51 +88,145 @@ program day12
print *, "Total valid: ", total_valid print *, "Total valid: ", total_valid
contains contains
function consistent(springs, n_spr, specs, n_specs) function nvalid(springs, n_spr, specs, n_specs) result(nv)
implicit none implicit none
character(*), intent(in) ::springs character(*), intent(in) :: springs
integer, intent(in) :: specs(:) integer, intent(in) :: specs(:)
integer, intent(in) :: n_spr, n_specs integer, intent(in) :: n_spr, n_specs
logical :: consistent integer :: nv
integer :: c1, c2, c3, i, speccur, clen integer :: ex_dist, i, cur
cur = 0
consistent = .true. do i=1, n_specs
c1 = 1 cur = cur + specs(i) + 1
speccur = 0
do i = 1, n_spr
if (c1 .gt. n_spr) then
consistent = speccur .eq. n_specs
! We've run out of springs
return
end if
c2 = scan(springs(c1:n_spr), '#')
if (c2 .eq. 0) then
consistent = speccur .eq. n_specs
! Also run out of springs
return
end if
c2 = c1 + c2 - 1
c3 = verify(springs(c2:n_spr), '#')
if (c3 .eq. 0) then
! Ends at end of string
c3 = n_spr
else
c3 = c2 + c3 - 2
end if
speccur = speccur + 1
if (speccur .gt. n_specs) then
consistent = .false.
return
end if
clen = c3 - c2 + 1
if (clen .ne. specs(speccur)) then
consistent = .false.
return
end if
c1 = c3 + 1
end do end do
print *, '???' ex_dist = n_spr - cur + 1
end function consistent print *, "Budget: ", ex_dist
print *, "Cnk: ", n_specs + ex_dist, ex_dist
nv = n_specval(springs, n_spr, specs, n_specs, 0, ex_dist, 1)
end function nvalid
recursive function n_specval(springs, n_spr, specs, n_specs, i_gap, budget, cur) result(nsv)
implicit none
integer, intent(in) :: n_spr, n_specs, i_gap, budget, cur
integer, intent(in) :: specs(:)
character(*), intent(in) :: springs
integer :: nsv
integer :: b_used, cur2, curnew, brem
logical :: bad
if (i_gap .eq. n_specs) then
! Working on the last gap; all good so far
if (budget .eq. 0) then
! Nothing to consider
nsv = 1
else if (scan(springs((n_spr - budget + 1):n_spr), '#') .ne. 0) then
nsv = 0
else
nsv = 1
end if
return
end if
nsv = 0
do b_used=0,budget
cur2 = cur + b_used
if (i_gap .lt. 7) then
print *, i_gap, b_used, cur2, repeat('*', i_gap + 1)
end if
curnew = cur2 + specs(i_gap + 1) + 1
bad = .false.
if (.not. mem_specval(cur2, specs(i_gap + 1), springs, n_spr)) then
! Bad placement
bad = .true.
end if
if ((.not. bad) .and. (b_used .gt. 0)) then
if (scan(springs(cur:(cur2-1)), '#') .ne. 0) then
! Something between
bad = .true.
end if
end if
if (.not. bad) then
brem = budget - b_used
nsv = nsv + n_specval(springs, n_spr, specs, n_specs, i_gap + 1, brem, curnew)
end if
end do
end function n_specval
subroutine pr_specs(n_spr, n_specs, specs, s_starts)
implicit none
integer, intent(in) :: n_spr, n_specs, specs(:), s_starts(:)
character(len=max_chars) :: pstr
integer :: i
pstr = ' '
pstr(1:n_spr) = repeat('.', n_spr)
do i=1,n_specs
pstr(s_starts(i):(s_starts(i) + specs(i) - 1)) = repeat('#', specs(i))
end do
print *, trim(pstr)
end subroutine pr_specs
function spec_test(specs, spec_starts, n_specs, springs, n_spr)
implicit none
integer, intent(in) :: specs(:), spec_starts(:), n_specs, n_spr
character(*), intent(in) :: springs
logical :: spec_test
integer :: i
spec_test = .true.
do i=1,n_specs
if (.not. specval(spec_starts(i), specs(i), springs, n_spr)) then
spec_test = .false.
return
end if
end do
end function spec_test
function mem_specval(spec_start, spec_len, springs, n_spr)
implicit none
integer, intent(in) :: spec_start, spec_len, n_spr
character(*), intent(in) :: springs
logical :: mem_specval
if (cache(spec_len, spec_start) .eq. -1) then
mem_specval = specval(spec_start, spec_len, springs, n_spr)
if (mem_specval) then
cache(spec_len, spec_start) = 1
else
cache(spec_len, spec_start) = 0
end if
else if (cache(spec_len, spec_start) .eq. 0) then
mem_specval = .false.
else
mem_specval = .true.
end if
end function mem_specval
function specval(spec_start, spec_len, springs, n_spr)
implicit none
integer, intent(in) :: spec_start, spec_len, n_spr
character(*), intent(in) :: springs
logical :: specval
integer :: spec_end, pos
spec_end = spec_start + spec_len - 1
if (spec_end .gt. n_spr) then
specval = .false.
return
end if
pos = scan(springs(spec_start:spec_end), '.')
if (pos .ne. 0) then
specval = .false.
return
end if
if (spec_start .gt. 0) then
if (springs((spec_start-1):(spec_start-1)) .eq. '#') then
specval = .false.
return
end if
end if
if (spec_end .lt. n_spr) then
if (springs((spec_end+1):(spec_end+1)) .eq. '#') then
specval = .false.
return
end if
end if
specval = .true.
end function specval
function numstr(springs, str) function numstr(springs, str)
implicit none implicit none
@ -145,81 +242,21 @@ program day12
end do end do
end function numstr end function numstr
function viable(springs, n_spr, specs, n_specs) function Cnk(n, k)
implicit none implicit none
character(*), intent(in) ::springs integer, intent(in) :: n, k
integer, intent(in) :: specs(:) integer :: Cnk
integer, intent(in) :: n_spr, n_specs integer :: i
logical :: viable integer :: num, den
character(len=1) :: ch num = 1
integer :: i, i2, spi, spc, nrq, remt do i = 0, k-1
logical :: ch1v, ch2v num = num * (n-i)
spi = 0
spc = 0
viable = .true.
ch2v = .false.
do i=1,n_spr
ch1v = ch2v
ch = springs(i:i)
if (ch .eq. '?') then
nrq = numstr(springs(i:n_spr), '?#')
remt = 0
do i2=spi,n_specs
remt = remt + specs(i2)
end do end do
remt = remt - spc den = 1
viable = (nrq .ge. remt) do i = 1, k
return den = den * i
end if
ch2v = scan(ch, '#') .ne. 0
if (ch2v) then
if (ch1v) then
spc = spc + 1
if (spc .gt. specs(spi)) then
viable = .false.
return
end if
else
spc = 1
spi = spi + 1
if (spi .gt. n_specs) then
viable = .false.
return
end if
end if
end if
end do end do
end function viable Cnk = num/den
end function Cnk
recursive function nvalid(springs, n_spr, specs, n_specs, r_branch) result(nv)
implicit none
character(len=max_chars), intent(in) ::springs
integer, intent(in) :: specs(:)
integer, intent(in) :: n_spr, n_specs
logical, intent(in) :: r_branch
integer :: nv
integer :: s_pos
character(len=max_chars) :: test_spr
nv = 0
s_pos = scan(springs, '?')
if (r_branch) then
print *, "Right branch depth: ", s_pos
end if
if (s_pos .eq. 0) then
if (consistent(springs, n_spr, specs, n_specs)) then
nv = nv + 1
end if
return
end if
test_spr = springs
test_spr(s_pos:s_pos) = '#'
if (viable(test_spr, n_spr, specs, n_specs)) then
nv = nv + nvalid(test_spr, n_spr, specs, n_specs, .false.)
end if
test_spr(s_pos:s_pos) = '.'
if (viable(test_spr, n_spr, specs, n_specs)) then
nv = nv + nvalid(test_spr, n_spr, specs, n_specs, r_branch)
end if
end function nvalid
end program day12 end program day12