added next day

11/solve02.py

@@ -0,0 +1,44 @@
+#!/usr/bin/env python
+
+from collections import defaultdict
+
+SIZE=300
+SERIAL=8444
+
+def get_cell_power(x, y, serial):
+    rack_id = x + 10
+    power = rack_id * y
+    power += serial
+    power *= rack_id
+    
+    h = str(power)[-3] if power > 100 else '0'
+    return int(h) - 5
+
+# creating summed area table
+# https://en.wikipedia.org/wiki/Summed-area_table
+def create_field(serial):
+    f = defaultdict(int)
+    for y in range(1, SIZE+1):
+        for x in range(1, SIZE+1):
+            p = get_cell_power(x,y,serial)
+            f[(x,y)] = f[(x-1,y)] + f[(x, y-1)] - f[(x-1,y-1)] + p
+    return f
+
+def get_region_sum(t,x,y,s):
+    (x1, y1) = (x-1, y -1)
+    (x2, y2) = (x + s -1, y + s - 1)
+    return t[(x1,y1)] + t[(x2, y2)] - t[(x1, y2)] - t[(x2, y1)]
+
+def get_best(t, s):
+    rs = []
+    for y in range(1, SIZE -s + 2):
+        for x in range(1, SIZE -s +2):
+            r = get_region_sum(t, x, y, s)
+            rs.append((r,x,y,s))
+    return max(rs)
+
+
+t = create_field(SERIAL)
+print("%d,%d" % get_best(t, 3)[1:3])
+
+print("%d,%d,%d" % max([get_best(t, s) for s in range(1, SIZE+1)])[1:])