Do day 15.

README.md

@@ -13,8 +13,8 @@
 - Day 11: 68:00; okay but not elegant and way too slow ofc; x-ray solution would have been neat
 - Day 12: 52:00 and 22:00 for leaderboard; had the right idea and I am good at this type of problem
 - Day 13: 90:00; pretty straightforward  but way too slow
-- Day 14:
-- Day 15:
+- Day 14: 5:55 for first and then 48:00; straightforward but slow, ofc
+- Day 15: 4:30 and 31:20; more reading comprehension than programming
 - Day 16: 00:27:30 745; best placement so far, of course still horribly slow
 - Day 17: a couple of hours; I realized that I need A* after a while; reused
   implementation from Project Euler but improved with heapq which was super fun
@@ -22,3 +22,4 @@
   but didn't realize that I have to compute the outer edges for a while and
   after I did, I still got clockwise/counter-clockwise issues. They could have
   made it meaner by using different clock directions for example and input.
+- Day 19: 

d15.py

@@ -0,0 +1,71 @@
+from lib import *
+from collections import OrderedDict
+
+EXAMPLE = "rn=1,cm-,qp=3,cm=2,qp-,pc=4,ot=9,ab=5,pc-,pc=6,ot=7"
+
+def hash(word):
+    # Init to 0
+    #   Determine the ASCII code for the current character of the string.
+    #   Increase the current value by the ASCII code you just determined.  Set
+    #   the current value to itself multiplied by 17.  Set the current value to
+    #   the remainder of dividing itself by 256.
+    h = 0
+    for c in word:
+        v = ord(c)
+        h += v
+        h *= 17
+        h %= 256
+    return h
+
+def solve(input: Input, second=False):
+    res = 0
+    line = input.lines()[0]
+    for word in line.split(","):
+        h = hash(word)
+        res += h
+
+    if not second:
+        return res
+
+    boxes = [OrderedDict() for _ in range(256)]
+    for word in line.split(","):
+        h = hash(word)
+        if '=' in word:
+            label, focal = word.split('=')
+            box = boxes[hash(label)]
+            if label in box:
+                box[label] = (label, focal)
+            else:
+                box[label] = (label, focal)
+        elif '-' in word:
+            label = word.replace('-', '')
+            box = boxes[hash(label)]
+            if label in box:
+                del box[label]
+        else:
+            raise Exception()
+
+    res = 0
+    for i, b in enumerate(boxes):
+        for j, label in enumerate(b):
+            label, focal = b[label]
+            r = (i + 1) * (j + 1) * int(focal)
+            res += r
+    return res
+
+def main():
+    DAY_INPUT = "i15.txt"
+
+    print("Example  1:", solve(Input(EXAMPLE)))
+    print("Solution 1:", solve(Input(DAY_INPUT)))
+    assert solve(Input(DAY_INPUT)) == 511343
+    # 4:30
+
+    print("Example  2:", solve(Input(EXAMPLE), True))
+    print("Solution 2:", solve(Input(DAY_INPUT), True))
+    assert solve(Input(DAY_INPUT), True) == 294474
+    # 31:20
+    return
+
+if __name__ == "__main__":
+    main()

d19.py

@@ -0,0 +1,30 @@
+from lib import *
+
+EXAMPLE = """
+"""
+
+def solve(i: Input, second=False):
+    res = 0
+    i.stats()
+    # g = i.grid2()
+    # ls = i.lines()
+    # ps = i.paras()
+    return res
+
+def main():
+    DAY_INPUT = "i19.txt"
+
+    print("Example  1:", solve(Input(EXAMPLE)))
+    return
+
+    print("Solution 1:", solve(Input(DAY_INPUT)))
+    return
+
+    print("Example  2:", solve(Input(EXAMPLE), True))
+    return
+
+    print("Solution 2:", solve(Input(DAY_INPUT), True))
+    return
+
+if __name__ == "__main__":
+    main()