2023 Dec 17th

Python/2023/17/main.py

@@ -0,0 +1,34 @@
+from heapq import heappush, heappop
+
+input = open("input", 'r')
+
+d = [[int(num) for num in line.rstrip()] for line in input]
+hgt = len(d)
+wdt = len(d[0])
+
+def dkstr(mn=1,mx=3):
+    s = set()
+    q = [(0,0,0,0,0)]
+    while q:
+        h,x,y,dx,dy = heappop(q)
+        if (x,y,dx,dy) in s:
+            continue
+        if (x,y) == (wdt-1,hgt-1):
+            return h
+        s.add((x,y,dx,dy))
+        for ndx, ndy in [(0,1),(0,-1),(1,0),(-1,0)]:
+            if (ndx, ndy) == (dx,dy) or (ndx,ndy) == (-dx,-dy):
+                continue
+            nx, ny, nh = x, y, h
+            for i in range(1,mx+1):
+                nx += ndx
+                ny += ndy
+                if (nx < 0 or nx >= wdt) or (ny < 0 or ny >= hgt):
+                    break
+                nh += d[ny][nx]
+                if i >= mn:
+                    heappush(q, (nh,nx,ny,ndx,ndy))
+    return -1
+
+print(dkstr())
+print(dkstr(4,10))