From 8db7b93c25aa5697ae47a4584a6c72b3e67965f9 Mon Sep 17 00:00:00 2001
From: Ben Charlton <ben@spod.cx>
Date: Fri, 6 Dec 2019 19:17:46 +0000
Subject: [PATCH] day5

---
 5/5.py | 109 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 109 insertions(+)
 create mode 100755 5/5.py

diff --git a/5/5.py b/5/5.py
new file mode 100755
index 0000000..8f1fd93
--- /dev/null
+++ b/5/5.py
@@ -0,0 +1,109 @@
+#!/usr/bin/env python3
+
+import sys
+
+startval = 1
+
+# pass in start value
+if len(sys.argv) == 2:
+  startval=sys.argv[1]
+
+def r(inst, pos, mode):
+  if mode == 0:
+    return int(inst[inst[pos]])
+  else: 
+    return int(inst[pos])
+
+def w(inst, pos, v, mode):
+  if mode == 0:
+    inst[inst[pos]] = v
+  else:
+    print("broken!", inst, pos, v, mode)
+
+def perform(inst):
+  pos = 0
+  store = startval
+  while 1:
+    incr = 4
+    fullopcode = inst[pos]
+    opcode = fullopcode % 100
+    mode_c = (int(fullopcode/100) % 10)
+    mode_b = (int(fullopcode/1000) % 10)
+    mode_a = (int(fullopcode/10000) % 10)
+    pos_c = pos+1
+    pos_b = pos+2
+    pos_a = pos+3
+
+    print("OP:", opcode, mode_c, mode_b, mode_a, pos_c, pos_b, pos_a)
+
+    # add
+    if opcode == 1:
+      val = r(inst,pos_c,mode_c) + r(inst,pos_b,mode_b)
+      w(inst, pos_a, val, mode_a)
+
+    # multiply
+    elif opcode == 2:
+      val = r(inst,pos_c, mode_c) * r(inst,pos_b, mode_b)
+      w(inst, pos_a, val, mode_a)
+
+    # input
+    elif opcode == 3:
+      w(inst, pos_c, store, mode_c)
+      incr = 2
+
+    # output
+    elif opcode == 4:
+      store = r(inst,pos_c, mode_c)
+      incr = 2
+
+    # jump-if-true
+    elif opcode == 5:
+      t = int(r(inst,pos_c, mode_c))
+      if t != 0:
+        pos = int(r(inst,pos_b, mode_b))
+        incr = 0
+      else:
+        incr = 3
+
+    # jump-if-false
+    elif opcode == 6:
+      t = int(r(inst,pos_c, mode_c))
+      if t == 0:
+        pos = int(r(inst,pos_b, mode_b))
+        incr = 0
+      else:
+        incr = 3
+
+    # less-than
+    elif opcode == 7:
+      c = int(r(inst,pos_c, mode_c))
+      b = int(r(inst,pos_b, mode_b))
+      if c < b:
+        w(inst, pos_a, 1, mode_a)
+      else:
+        w(inst, pos_a, 0, mode_a)
+
+    # equals
+    elif opcode == 8:
+      c = int(r(inst,pos_c, mode_c))
+      b = int(r(inst,pos_b, mode_b))
+      if c == b:
+        w(inst, pos_a, 1, mode_a)
+      else:
+        w(inst, pos_a, 0, mode_a)
+
+    # stop
+    elif opcode == 99:
+      break
+
+    pos += incr
+  return inst[0], store
+
+for line in sys.stdin:
+  instructions = line.rstrip().split(',')
+
+  ints = []
+  for i in instructions:
+    ints.append(int(i))
+  res = perform(ints)
+  print(res)