2017 day 14 solution

Signed-off-by: Lance-Drane <ldraneutk@gmail.com>

2017/10/2.py

@@ -21,9 +21,6 @@
         current_position = (forward + skip_size) % LIST_SIZE
         skip_size += 1
 
-hex_arr = [format(reduce(lambda x, y: x ^ y, nums[idx : idx + 16]), 'x') for idx in range(0, 256, 16)]
-for idx, item in enumerate(hex_arr):
-    if len(item) == 1:
-        hex_arr[idx] = f'0{item}'
+hex_arr = [format(reduce(lambda x, y: x ^ y, nums[idx : idx + 16]), 'x').zfill(2) for idx in range(0, 256, 16)]
 
 print(''.join(hex_arr))

2017/14/1.py

@@ -0,0 +1,30 @@
+from functools import reduce
+
+LIST_SIZE = 256
+
+base = f'{input()}-'
+
+used_squares = 0
+for row in range(128):
+    nums = list(range(LIST_SIZE))
+    current_position = 0
+    skip_size = 0
+    lengths = [ord(x) for x in f'{base}{row}'] + [17, 31, 73, 47, 23]
+    for _ in range(64):
+        for length in lengths:
+            forward = current_position + length
+            if forward > LIST_SIZE:
+                last_idx = forward % LIST_SIZE
+                sublist = nums[current_position:] + nums[:last_idx]
+                sublist = sublist[::-1]
+                sublist_breakpoint = (len(sublist) - last_idx) % len(sublist)
+                nums = sublist[sublist_breakpoint:] + nums[last_idx:current_position] + sublist[:sublist_breakpoint]
+            else:
+                nums = nums[:current_position] + nums[current_position:forward][::-1] + nums[forward:]
+            current_position = (forward + skip_size) % LIST_SIZE
+            skip_size += 1
+
+    bin_arr = [format(reduce(lambda x, y: x ^ y, nums[idx : idx + 16]), 'b').zfill(8) for idx in range(0, 256, 16)]
+    used_squares += sum(x.count('1') for x in bin_arr)
+
+print(used_squares)

2017/14/1_out.txt

@@ -0,0 +1 @@
+8316

2017/14/2.py

@@ -0,0 +1,58 @@
+from functools import reduce
+
+LIST_SIZE = 256
+
+base = f'{input()}-'
+
+grid = []
+for row in range(128):
+    nums = list(range(LIST_SIZE))
+    current_position = 0
+    skip_size = 0
+    lengths = [ord(x) for x in f'{base}{row}'] + [17, 31, 73, 47, 23]
+    for _ in range(64):
+        for length in lengths:
+            forward = current_position + length
+            if forward > LIST_SIZE:
+                last_idx = forward % LIST_SIZE
+                sublist = nums[current_position:] + nums[:last_idx]
+                sublist = sublist[::-1]
+                sublist_breakpoint = (len(sublist) - last_idx) % len(sublist)
+                nums = sublist[sublist_breakpoint:] + nums[last_idx:current_position] + sublist[:sublist_breakpoint]
+            else:
+                nums = nums[:current_position] + nums[current_position:forward][::-1] + nums[forward:]
+            current_position = (forward + skip_size) % LIST_SIZE
+            skip_size += 1
+
+    bin_arr = [format(reduce(lambda x, y: x ^ y, nums[idx : idx + 16]), 'b').zfill(8) for idx in range(0, 256, 16)]
+    grid.append(list(''.join(bin_arr)))
+
+groups = 0
+for y in range(128):
+    for x in range(128):
+        if grid[y][x] == '0':
+            continue
+        grid[y][x] = '0'
+        stack = [(y, x)]
+        while stack:
+            curr_y, curr_x = stack.pop()
+            # top
+            if curr_y > 0 and grid[curr_y - 1][curr_x] == '1':
+                grid[curr_y - 1][curr_x] = '0'
+                stack.append((curr_y - 1, curr_x))
+            # right
+            if curr_x < 127 and grid[curr_y][curr_x + 1] == '1':
+                grid[curr_y][curr_x + 1] = '0'
+                stack.append((curr_y, curr_x + 1))
+            # bottom
+            if curr_y < 127 and grid[curr_y + 1][curr_x] == '1':
+                grid[curr_y + 1][curr_x] = '0'
+                stack.append((curr_y + 1, curr_x))
+            # left
+            if curr_x > 0 and grid[curr_y][curr_x - 1] == '1':
+                grid[curr_y][curr_x - 1] = '0'
+                stack.append((curr_y, curr_x - 1))
+
+        groups += 1
+
+print(groups)

2017/14/2_out.txt

@@ -0,0 +1 @@
+1074

2017/14/in.txt

@@ -0,0 +1 @@
+ljoxqyyw