1 files changed, 62 insertions, 0 deletions
diff --git a/2020/aoc2020-d11.py b/2020/aoc2020-d11.py
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+++ b/2020/aoc2020-d11.py
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+#advent of code 2020
+#day 11
+
+directions = [(-1,-1),(-1,0),(-1,1),(0,-1),(0,1),(1,-1),(1,0),(1,1)];
+
+#for part 1
+def scan1(grid,pos):
+	around = "";
+	y,x = pos;
+	for dy,dx in directions:
+		if (y+dy,x+dx) not in grid: continue;
+		around += grid[(y+dy,x+dx)];
+	return around;
+#for part 2
+def scan2(grid,pos):
+	around = "";
+	for dy,dx in directions:
+		y,x = pos;
+		while True:
+			x += dx;
+			y += dy;
+			if (y,x) not in grid: 
+				break;
+			elif grid[(y,x)] != ".":
+				around += grid[(y,x)];
+				break;
+	return around;
+
+#correct function is passed as an argument (scan)
+def simulate(grid,scan,lim):
+	score = 0;
+	while True:
+		gridDupe = dict();
+		for coordinates in grid:
+			state = grid[coordinates];
+			y,x = coordinates;
+			around = scan(grid,coordinates);
+			if around.count("#") == 0 and state == "L": 
+				gridDupe[coordinates] = "#";
+			elif around.count("#") >= lim and state == "#":
+				gridDupe[coordinates] = "L";
+		for dupe in gridDupe: 
+			grid[dupe] = gridDupe[dupe];
+		if len(gridDupe) == 0: 
+			break;
+	for coordinates in grid: 
+		if grid[coordinates] == "#": score += 1;
+	return score;
+
+grid1 = dict();
+PuzzleInput = open("11.in","r");
+for y,line in enumerate(PuzzleInput):
+	line = line[:-1];
+	for x, c in enumerate(line):
+		grid1[(y,x)] = c;
+PuzzleInput.close();
+grid2 = grid1.copy(); 
+
+p1 = simulate(grid1,scan1,4);
+p2 = simulate(grid2,scan2,5);
+print("part 1 =",p1);
+print("part 2 =",p2);