2023 Day 15

2023/Makefile

@@ -2,7 +2,7 @@ FC:=gfortran
 FFLAGS:=-Wall -Wno-maybe-uninitialized -O2
 BIN:=./bin
 SRC:=./src
-BINS:=./bin/day01.bin ./bin/day01b.bin ./bin/day02.bin ./bin/day03.bin ./bin/day04.bin ./bin/day05.bin ./bin/day05b.bin ./bin/day06.bin ./bin/day07.bin ./bin/day07b.bin ./bin/day08.bin ./bin/day08b.bin ./bin/day09.bin ./bin/day10.bin ./bin/day11.bin ./bin/day12.bin ./bin/day13.bin ./bin/day14.bin ./bin/day14b.bin
+BINS:=./bin/day01.bin ./bin/day01b.bin ./bin/day02.bin ./bin/day03.bin ./bin/day04.bin ./bin/day05.bin ./bin/day05b.bin ./bin/day06.bin ./bin/day07.bin ./bin/day07b.bin ./bin/day08.bin ./bin/day08b.bin ./bin/day09.bin ./bin/day10.bin ./bin/day11.bin ./bin/day12.bin ./bin/day13.bin ./bin/day14.bin ./bin/day14b.bin ./bin/day15.bin
 
 all: aoc19
 

2023/data/day15ex1.txt

@@ -0,0 +1 @@
+rn=1,cm-,qp=3,cm=2,qp-,pc=4,ot=9,ab=5,pc-,pc=6,ot=7

2023/src/day15.f90

@@ -0,0 +1,114 @@
+program day15
+    implicit none
+    integer, parameter :: max_chars = 100000
+    integer, parameter :: seq_chars = 100
+    integer, parameter :: max_seqs = 10000
+    character(200) :: fname
+    character(max_chars) :: fline
+    character(seq_chars) :: seqtext, label
+    integer :: n_arguments
+    integer :: istat
+    integer :: hashval, cpos_1, cpos_2, labend, hashtot, labhash
+    integer :: i, i2, strlen, n_placed, f_index, foc
+    logical :: found
+    integer :: boxno(1:max_seqs), focal(1:max_seqs), boxfound(0:255)
+    character(seq_chars) :: labels(1:max_seqs)
+    logical :: present(1:max_seqs)
+    integer :: focpow, totpow, tbox
+
+    n_arguments = command_argument_count()
+    if (n_arguments .eq. 1) then
+        call get_command_argument(1, fname)
+        print *, "File: ", trim(fname)
+        print *
+    else
+        print *, "Wrong number of arguments: ", n_arguments
+        stop
+    end if
+    open(10, file=fname)
+    read(10, "(a)", iostat=istat) fline
+    close(10)
+
+    cpos_2 = 0
+    strlen = len_trim(fline)
+    hashtot = 0
+    present = .false.
+    n_placed = 0
+    do i=1,max_seqs
+        cpos_1 = cpos_2
+        cpos_2 = scan(fline((cpos_1+1):strlen), ',')
+        if (cpos_2 .eq. 0) then
+            cpos_2 = strlen + 1
+        else
+            cpos_2 = cpos_2 + cpos_1
+        end if
+        seqtext = fline((cpos_1+1):(cpos_2-1))
+        hashval = HASH(seqtext)
+        labend = scan(seqtext, '=-')
+        label = seqtext(1:(labend-1))
+        labhash = HASH(label)
+        print *, trim(seqtext), hashval, trim(label), labhash
+        hashtot = hashtot + hashval
+        found = .false.
+        do i2=1,n_placed
+            if ((boxno(i2) .eq. labhash) .and. (trim(labels(i2)) .eq. trim(label)) .and. present(i2)) then
+                found = .true.
+                f_index = i2
+                exit
+            end if
+        end do
+        if (seqtext(labend:labend) .eq. '-') then
+            if (found) then
+                present(f_index) = .false.
+                print *, "Delete ", trim(label), " at", boxno(f_index), f_index
+            else
+                print *, trim(label), " not found in box", labhash
+            end if
+        else
+            read(seqtext((labend+1):(labend+1)), *) foc
+            if (found) then
+                focal(f_index) = foc
+                print *, "Replace ", trim(label), " at", boxno(f_index), f_index
+            else
+                n_placed = n_placed + 1
+                boxno(n_placed) = labhash
+                labels(n_placed) = label
+                focal(n_placed) = foc
+                present(n_placed) = .true.
+                print *, "Place ", trim(label), ' at', labhash, n_placed, ' with', foc
+            end if
+        end if
+        if (cpos_2 .ge. strlen) then
+            exit
+        end if
+    end do
+    print *, "Total hash: ", hashtot
+    print *, "Number of lenses: ", i
+    boxfound = 0
+    totpow = 0
+    do i=1, n_placed
+        if (present(i)) then
+            tbox = boxno(i)
+            foc = focal(i)
+            boxfound(tbox) = boxfound(tbox) + 1
+            focpow = (tbox + 1) * boxfound(tbox) * foc
+            print *, tbox, boxfound(tbox), ' ', trim(labels(i)), foc, focpow
+            totpow = totpow + focpow
+        end if
+    end do
+    print *, "Total focal power: ", totpow
+
+    contains
+        function HASH(str)
+            implicit none
+            character(*), intent(in) :: str
+            integer :: HASH
+            integer :: i, strlen
+            strlen = len_trim(str)
+            HASH = 0
+            do i=1,strlen
+                HASH = mod((HASH + iachar(str(i:i))) * 17, 256)
+            end do
+        end function HASH
+end program day15
+