Day 13 part 2

13/13_2.py

@@ -0,0 +1,110 @@
+#!/usr/bin/env python
+# 2021 - Advent Of Code - 13 part 2
+
+
+def parse_file(file):
+    parsed_dots = []
+    parsed_folds = []
+    with open(file) as f:
+        for line in f.readlines():
+            if line.startswith('fold along '):
+                _, f = line.strip().split('fold along ')
+                parsed_folds.append(f.split('='))
+            elif line == '\n':
+                pass
+            else:
+                dot = [int(d) for d in line.strip().split(',')]
+                parsed_dots.append(dot)
+        return parsed_dots, parsed_folds
+
+
+def find_max(dot_list):
+    mx = 0
+    my = 0
+    for d in dot_list:
+        if d[0] > mx:
+            mx = d[0]
+        if d[1] > my:
+            my = d[1]
+
+    return mx, my
+
+
+def place_dots(g, dots_list):
+    for dot in dots_list:
+        g[dot[1]][dot[0]] = 1
+
+
+def print_grid(g):
+    for y, _ in enumerate(g):
+        for x, _ in enumerate(g[y]):
+            if g[y][x] == 1:
+                print('#', end='')
+            else:
+                print('.', end='')
+        print()
+
+
+def fold_horizontally(g, fold_y, g_maxy):
+    print(f'folding y={fold_y}')
+    for y in range(fold_y, g_maxy+1):
+        folding_dist = y - fold_y
+        new_y = fold_y - folding_dist
+
+        # place new dots
+        for x, _ in enumerate(g[y]):
+            if g[y][x] == 1:
+                g[new_y][x] = 1
+
+    # cut the other half of the grid
+    for _ in range(fold_y+1):
+        g.pop()
+    return fold_y-1
+
+
+def fold_vertically(g, fold_x, g_maxx):
+    print(f'folding x={fold_x}')
+    for y, _ in enumerate(g):
+        # place new dots
+        for x in range(fold_x, g_maxx+1):
+            folding_dist = x - fold_x
+            new_x = fold_x - folding_dist
+            if g[y][x] == 1:
+                g[y][new_x] = 1
+
+        # cut the other half of the grid
+        g[y] = g[y][:fold_x]
+    return fold_x-1
+
+
+def count_dots(g):
+    count = 0
+    for y, _ in enumerate(g):
+        for x, _ in enumerate(g[y]):
+            if g[y][x] == 1:
+                count += 1
+
+    return count
+
+
+# dots, folds = parse_file('input_example.txt')
+dots, folds = parse_file('input.txt')
+
+maxx, maxy = find_max(dots)
+grid = [[0] * (maxx+1) for _ in range(maxy+1)]
+
+place_dots(grid, dots)
+print(f'grid size: {maxx}, {maxy}')
+print(f'real grid size: {len(grid[0])}, {len(grid)}')
+print()
+
+for fold in folds:
+    if fold[0] == 'x':
+        maxx = fold_vertically(grid, int(fold[1]), maxx)
+    else:
+        maxy = fold_horizontally(grid, int(fold[1]), maxy)
+    print(f'grid size: {maxx}, {maxy}')
+    print(f'real grid size: {len(grid[0])}, {len(grid)}')
+    print()
+
+print_grid(grid)