Solve 2016 day 11.

2016/d11.py

@@ -0,0 +1,89 @@
+import sys
+from itertools import combinations
+from lib import *
+
+TOP_FLOOR = 3
+part_1 = False
+if part_1:
+    #        g0, c0, g1, c1, ...         elevator 
+    state = [0, 0, 1, 2, 1, 2, 1, 2, 1, 2, 0]
+else:
+    state = [0, 0, 0, 0, 0, 0, 1, 2, 1, 2, 1, 2, 1, 2, 0]
+
+
+def is_state_valid(state):
+    for floor in range(0, TOP_FLOOR + 1):
+        gens_on_floor = [i // 2 for i in range(0, len(state) - 1, 2) if state[i] == floor]
+        chips_on_floor = [i // 2 for i in range(1, len(state) - 1, 2) if state[i] == floor]
+        if len(gens_on_floor) > 0:
+            for c in chips_on_floor:
+                if not c in gens_on_floor:
+                    return False
+    return True
+
+assert is_state_valid([0, 0, 1, 2, 1, 2, 1, 2, 1, 2, 0]) == True
+assert is_state_valid([0, 0, 1, 0, 1, 2, 1, 2, 1, 2, 0]) == False
+
+
+def is_end_state(state):
+    return all([o == TOP_FLOOR for o in state])
+
+assert is_end_state([0, 0, 1, 0, 1, 2, 1, 2, 1, 2, 0]) == False
+assert is_end_state([3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3]) == True
+
+
+def next_states(state):
+    floor = state[-1]
+    objects_on_floor = [i for i in range(len(state) - 1) if state[i] == floor]
+
+    nstates = []
+    for o in objects_on_floor:
+        if floor > 0:
+            nstate = list(state)
+            nstate[o] -= 1
+            nstate[-1] -= 1
+            nstates.append(nstate)
+        if floor < TOP_FLOOR:
+            nstate = list(state)
+            nstate[o] += 1
+            nstate[-1] += 1
+            nstates.append(nstate)
+
+    for os in combinations(objects_on_floor, 2):
+        if floor > 0:
+            nstate = list(state)
+            for o in os:
+                nstate[o] -= 1
+            nstate[-1] -= 1
+            nstates.append(nstate)
+        if floor < TOP_FLOOR:
+            nstate = list(state)
+            for o in os:
+                nstate[o] += 1
+            nstate[-1] += 1
+            nstates.append(nstate)
+    return nstates
+
+
+states = [state]
+for step in range(1000):
+    nstates = []
+    seen = set()
+    for state in states:
+
+        statet = tuple(state)
+        if statet in seen:
+            continue
+        seen.add(statet)
+
+        for nstate in next_states(state):
+            if not is_state_valid(nstate):
+                continue
+            if is_end_state(nstate):
+                print(step + 1)
+                sys.exit(0)
+            nstates.append(nstate)
+
+    # Keep search space manageable with pretty bad pruning.
+    nstates.sort(reverse=True)
+    states = nstates[:20000]

README.md

@@ -42,5 +42,6 @@ written in Python.
 - Day 7: 31:20 hmm
 - Day 8: 14:50 meh
 - Day 9: 26:00 okay
-- Day 10: 23:07
-- Day 11: 
+- Day 10: 23:07 okay
+- Day 11: 75:00 -__-
+- Day 12: