Day 15 Python solutions

Author: creideiki

15-1.py

@@ -0,0 +1,66 @@
+#!/usr/bin/env python
+
+import numpy
+
+class Map:
+    def __init__(self, input):
+        self.size = len(input)
+        self.map = numpy.zeros((self.size, self.size), dtype=numpy.uint)
+        self.risk = numpy.empty((self.size, self.size), dtype=numpy.uint)
+        self.risk.fill(pow(2, 32) - 1)
+
+        for row in range(len(input)):
+            for col in range(len(input)):
+                self.map[row, col] = int(input[row][col])
+
+    def find_risk(self):
+        queue = []
+        for row in range(self.size):
+            for col in range(self.size):
+                queue.append((row, col))
+        self.risk[0, 0] = 0
+
+        while len(queue) > 0:
+            min_risk = pow(2, 32)
+            min_coords = (0, 0)
+            min_index = 0
+            for index in range(len(queue)):
+                risk = self.risk[queue[index][0], queue[index][1]]
+                if risk < min_risk:
+                    min_risk = risk
+                    min_coords = (queue[index][0], queue[index][1])
+                    min_index = index
+            del queue[min_index]
+            u = min_coords
+
+            ns = [
+                [u[0] + 1, u[1]],
+                [u[0] - 1, u[1]],
+                [u[0], u[1] + 1],
+                [u[0], u[1] - 1]
+            ]
+
+            neighbours = []
+            for n in ns:
+                if n[0] >= 0 and \
+                   n[0] < self.size and \
+                   n[1] >= 0 and \
+                   n[1] < self.size and \
+                   (n[0], n[1]) in queue:
+                    neighbours.append((n[0], n[1]))
+            for v in neighbours:
+                alt = self.risk[u[0], u[1]] + self.map[v[0], v[1]]
+                if alt < self.risk[v[0], v[1]]:
+                    self.risk[v[0], v[1]] = alt
+
+        return self.risk[self.size - 1, self.size - 1]
+
+    def __str__(self):
+        return f"<{self.__class__.__name__}:\Size: {self.size}\n{self.map}\n>"
+
+
+lines = [list(line.strip()) for line in open('15.input').readlines()]
+
+map = Map(lines)
+
+print(map.find_risk())

15-2.py

@@ -0,0 +1,65 @@
+#!/usr/bin/env python
+
+import heapq
+import numpy
+
+class Map:
+    def __init__(self, input):
+        tile_size = len(input)
+        self.size = tile_size * 5
+        self.map = numpy.zeros((self.size, self.size), dtype=numpy.uint)
+        self.risk = numpy.empty((self.size, self.size), dtype=numpy.uint)
+        self.risk.fill(pow(2, 32) - 1)
+
+        for row in range(len(input)):
+            for col in range(len(input)):
+                for x in range(5):
+                    for y in range(5):
+                        r = int(input[row][col]) + x + y
+                        if r > 9:
+                            r -= 9
+                        self.map[row + tile_size * x, col + tile_size * y] = r
+
+    def find_risk(self):
+        self.risk[0, 0] = 0
+
+        queue = []
+        heapq.heappush(queue, (0, (0, 0)))
+
+        while len(queue) > 0:
+            risk, coords = heapq.heappop(queue)
+            x, y = coords
+            if risk > self.risk[x, y]:
+                continue
+
+            ns = [
+                [x + 1, y],
+                [x - 1, y],
+                [x, y + 1],
+                [x, y - 1]
+            ]
+
+            neighbours = []
+            for n in ns:
+                if n[0] >= 0 and \
+                   n[0] < self.size and \
+                   n[1] >= 0 and \
+                   n[1] < self.size:
+                    neighbours.append((n[0], n[1]))
+            for v in neighbours:
+                alt = risk + self.map[v[0], v[1]]
+                if alt < self.risk[v[0], v[1]]:
+                    self.risk[v[0], v[1]] = alt
+                    heapq.heappush(queue, (self.risk[v[0], v[1]], (v[0], v[1])))
+
+        return self.risk[self.size - 1, self.size - 1]
+
+    def __str__(self):
+        return f"<{self.__class__.__name__}:\Size: {self.size}\n{self.map}\n>"
+
+
+lines = [list(line.strip()) for line in open('15.input').readlines()]
+
+map = Map(lines)
+
+print(map.find_risk())