day 22

22/a.py

@@ -0,0 +1,87 @@
+#!/usr/bin/env python3
+
+
+from enum import Enum
+
+
+X = 0
+Y = 1
+GI = 0
+EL = 1
+TYPE = 2
+
+
+class Tile(Enum):
+    ROCKY = 0
+    WET = 1
+    NARROW = 2
+
+
+def main():
+    with open("input.txt") as f:
+        depth = int(f.readline().split(" ")[1])
+        target = tuple([int(i) for i in f.readline().split(" ")[1].split(",")])
+    # print(depth)
+    # print(target)
+
+    # depth = 510
+    # target = (10, 10)
+
+    target2 = (target[X] + 1, target[Y] + 1)
+
+    """
+    Type is based on erosion level (EL)
+    EL based on geologic index (GI)
+    GI based on rules
+
+    00 01 03 06 10 15
+    02 04 07 11 16 21
+    05 08 12 17 22 26
+    09 13 18 23 27 30
+    14 19 24 28 31 33
+    20 25 29 32 34 35
+
+
+    """
+    world = {}  # mapping of (x,y) to (GI, EL)
+
+    def calcGi(coord):
+        nonlocal world
+        if coord == (0, 0):
+            return 0  # gi hard coded to 0
+        elif coord == target:
+            return 0  # gi hard coded to 0
+        elif coord[Y] == 0:
+            return coord[X] * 16807  # X coordinate times 16807.
+        elif coord[X] == 0:
+            return coord[Y] * 48271  # Y coordinate times 48271.
+        else:
+            # result of multiplying the erosion levels of the regions at X-1,Y and X,Y-1.
+            return world[(coord[X] - 1, coord[Y])][EL] * world[(coord[X], coord[Y] - 1)][EL]
+
+    # https://stackoverflow.com/a/20422854
+    for k in range(0, target2[X] + target2[Y] - 1):
+        for y in range(0, k + 1):
+            x = k - y
+            if x < target2[X] and y < target2[Y]:
+                gi = calcGi((x, y))
+                el = (gi + depth) % 20183
+                world[(x,y)] = (gi, el, Tile(el % 3))
+                # print((x,y))
+
+    # print(world)
+
+    total = 0
+
+    for y in range(0, target[Y] + 1):
+        for x in range(0, target[X] + 1):
+            total += world[(x,y)][TYPE].value
+
+    print(total)
+
+    # populate world with risk values
+
+
+
+if __name__ == '__main__':
+    main()

22/input.txt

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+depth: 8112
+target: 13,743