day18/badmath.py

   1 #!/usr/bin/python3
   2
   3 import sys
   4
   5 filename="p1_71.txt"
   6 if len(sys.argv) > 1:
   7     filename=sys.argv[1]
   8
   9 def parse_sum(oursum):
  10     parts = oursum.split()
  11     new_parts=[]
  12     for part in parts:
  13         if part[0]=="(":
  14             for index,c in enumerate(part):
  15                 if c=="(":
  16                     new_parts.append("(")
  17                 else:
  18                     new_parts.append(part[index:])
  19                     break
  20         elif part[-1]==")":
  21             got_number=False
  22             for index,c in enumerate(part):
  23                 if c==")":
  24                     if not got_number:
  25                         new_parts.append(part[0:index])
  26                         got_number=True
  27                     new_parts.append(c)
  28         else:
  29             new_parts.append(part)
  30     return new_parts
  31
  32 def do_sum(parts):
  33     cur_total=0
  34     next_oper="+"
  35     bracketed=[]
  36     in_brackets=0
  37     for part in parts:
  38         if in_brackets > 0 and part != ")" and part != "(":
  39             bracketed.append(part)
  40             continue
  41         if in_brackets > 0 and part == ")":
  42             in_brackets-=1
  43             bracketed.append(part)
  44             if in_brackets == 0:
  45                 part=do_sum(bracketed[1:-1])
  46                 bracketed.clear()
  47             else:
  48                 continue
  49         if part == "+":
  50             next_oper="+"
  51         elif part == "*":
  52             next_oper="*"
  53         elif part == "(":
  54             in_brackets+=1
  55             bracketed.append(part)
  56         else:
  57             part=int(part)
  58             if next_oper == "+":
  59                 cur_total+=part
  60             else:
  61                 cur_total*=part
  62     return cur_total
  63
  64 total=0
  65 for line in [line.rstrip() for line in open(filename, "r")]:
  66     answer=do_sum(parse_sum(line))
  67     total+=answer
  68
  69 print("Part 1 Total:", total)