Day 15

2021/15.py

@@ -0,0 +1,60 @@
+import sys
+inf = sys.argv[1] if len(sys.argv) > 1 else './2021/15.input'
+
+ll = [[int(y) for y in x] for x in open(inf).read().strip().split('\n')]
+
+def inr(pos, arr):
+	return pos[0] in range(len(arr)) and pos[1] in range(len(arr[0]))
+
+q = [(0, 0, 0)]
+costs = {}
+while True:
+	cost,x,y = q[0]
+	if x==len(ll)-1 and y==len(ll[0])-1: 
+		print(cost)
+		break
+	q=q[1:]
+	for xx,yy in [(x+1,y),(x-1,y),(x,y-1),(x,y+1)]:
+		if inr((xx,yy),ll):
+			nc = cost + ll[xx][yy]
+			if (xx,yy) in costs and costs[(xx,yy)]<=nc:
+				continue
+			costs[(xx,yy)]=nc
+			q.append((nc,xx,yy))
+	q = sorted(q)
+
+ll = [[int(y) for y in x] for x in open(inf).read().strip().split('\n')]
+
+def inr(pos, arr):
+	return pos[0] in range(len(arr)) and pos[1] in range(len(arr[0]))
+
+expanded = [[0 for x in range(5*len(ll[0]))] for y in range(5*len(ll))]
+
+for x in range(len(expanded)):
+	for y in range(len(expanded[0])):
+		dist = x//len(ll) + y//len(ll[0])
+		newval = ll[x%len(ll)][y%len(ll[0])]
+		for i in range(dist):
+			newval+=1
+			if newval==10:
+				newval=1
+		expanded[x][y] = newval
+
+ll = expanded
+
+q = [(0, 0, 0)]
+costs = {}
+while True:
+	cost,x,y = q[0]
+	if x==len(ll)-1 and y==len(ll[0])-1: 
+		print(cost)
+		break
+	q=q[1:]
+	for xx,yy in [(x+1,y),(x-1,y),(x,y-1),(x,y+1)]:
+		if inr((xx,yy),ll):
+			nc = cost + ll[xx][yy]
+			if (xx,yy) in costs and costs[(xx,yy)]<=nc:
+				continue
+			costs[(xx,yy)]=nc
+			q.append((nc,xx,yy))
+	q = sorted(q)