From ca6e424946a769fa52f6950047c7e46aa6f1c781 Mon Sep 17 00:00:00 2001
From: Trey Bastian <2991824+TreyBastian@users.noreply.github.com>
Date: Tue, 3 Dec 2024 14:29:45 +0000
Subject: part2 done

---
 2024/day_03_part_2.f90 | 83 ++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 83 insertions(+)
 create mode 100644 2024/day_03_part_2.f90

(limited to '2024/day_03_part_2.f90')

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
-- 
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