2022 day 12

2022/12/part1

@@ -0,0 +1,63 @@
+#!/usr/bin/env python
+
+import math
+
+MAP = []
+START = (0, 0)
+END = (0, 0)
+DISTANCES = {}
+
+def possible(x, y):
+    global MAP
+
+    threshold = MAP[y][x] + 1 # Can't go higher than this, can always go lower
+    points = [(x-1,y),(x+1,y),(x,y-1),(x,y+1)]
+
+    out = []
+    for (x,y) in points:
+        if x < 0 or y < 0:
+            continue
+        if len(MAP) < y+1 or len(MAP[y]) < x+1:
+            continue
+        if MAP[y][x] > threshold:
+            continue
+
+        out.append((x,y))
+
+    return out
+
+with open('input') as f:
+    for y, line in enumerate(f):
+        row = []
+        for x, byte in enumerate(line.rstrip()):
+            DISTANCES[(x,y)] = math.inf
+            if byte == 'S':
+                byte = 'a'
+                START = (x,y)
+                DISTANCES[START] = 0
+            elif byte == 'E':
+                byte = 'z'
+                END = (x,y)
+            row.append(ord(byte) - ord('a'))
+        MAP.append(row)
+
+
+visited = set([])
+queue = [START]
+
+while len(queue) > 0:
+    pos = queue.pop(0)
+    visited.add(pos)
+
+    for neighbour in possible(*pos):
+        if neighbour == END:
+            print(DISTANCES[pos] + 1)
+            quit()
+
+        if DISTANCES[neighbour] > DISTANCES[pos] + 1:
+            DISTANCES[neighbour] = DISTANCES[pos] + 1
+
+        if neighbour not in visited and neighbour not in queue:
+            queue.append(neighbour)
+
+print("Couldn't find it!")