Day 13 in Python

Author: mlukaszek

day13.py

@@ -0,0 +1,49 @@
+import sys
+from collections import defaultdict
+
+def fold(paper, folds):
+    for (fx, fy) in folds:
+        for (hx, hy) in paper.copy():
+            if fy != 0 and hy > fy:
+                del paper[(hx, hy)]
+                paper[(hx, fy - (hy - fy))] = 1
+            elif fx != 0 and hx > fx:
+                del paper[(hx, hy)]
+                paper[(fx - (hx - fx), hy)] = 1            
+    return sum(paper.values())
+
+def printPaper(paper):
+    maxX = 1 + max([ hole[0] for hole in paper ])
+    maxY = 1 + max([ hole[1] for hole in paper ])
+    for j in range(maxY):
+        for i in range(maxX):
+            print("#" if paper[(i,j)] == 1 else " ", end="")
+        print()
+    print()
+
+def main(args = ()):
+    fileName = "day13.txt" if len(args) < 1 else args[0]
+
+    paper = defaultdict(int)
+    folds = []
+    with open(fileName) as lines:
+        for line in lines:
+            line = line.strip()
+            if "," in line:
+                x, y = [ int(i) for i in line.split(",") ]
+                paper[(x,y)] = 1
+            elif "x=" in line:
+                folds.append((int(line.split("=")[1]), 0))
+            elif "y=" in line:
+                folds.append((0, int(line.split("=")[1])))
+
+    part1 = fold(paper, [ folds.pop(0) ])
+    print("Part 1:", part1)
+
+    # part 2: continue folding
+    fold(paper, folds)
+    print("Part 2:")
+    printPaper(paper)
+
+if __name__ == "__main__":
+    sys.exit(main(sys.argv[1:]))