diff --git a/5/5_2.py b/5/5_2.py new file mode 100755 index 0000000..66a2e43 --- /dev/null +++ b/5/5_2.py @@ -0,0 +1,135 @@ +#!/usr/bin/env python +# 2021 - Advent Of Code - 5 part 2 + +def parse_file(file): + horizontal_lines = [] + vertical_lines = [] + diagonal_lines = [] + with open(file) as f: + for l in f.readlines(): + p1, p2 = l.strip().split(' -> ') + strx1, stry1 = p1.split(',') + strx2, stry2 = p2.split(',') + + # filter horizontal and vertical lines only + p1 = (int(strx1), int(stry1)) + p2 = (int(strx2), int(stry2)) + if strx1 == strx2: + vertical_lines.append([p1, p2]) + elif stry1 == stry2: + horizontal_lines.append([p1, p2]) + else: + diagonal_lines.append([p1, p2]) + + return horizontal_lines, vertical_lines, diagonal_lines + + +def draw_horizontal(g, hline): + + # print(f'drawing hline: {hline}') + if hline[0][0] < hline[1][0]: # left -> right + start_point = hline[0] + end_point = hline[1] + else: + start_point = hline[1] + end_point = hline[0] + + ly = start_point[1] + # print(f'drawing from {start_point[0]} to {end_point[0]}') + for lx in range(start_point[0], end_point[0]+1): + g[ly][lx] += 1 + + +def draw_vertical(g, vline): + # print(f'drawing vline: {vline}') + if vline[0][1] < vline[1][1]: # up -> down + start_point = vline[0] + end_point = vline[1] + else: + start_point = vline[1] + end_point = vline[0] + + lx = start_point[0] + # print(f'drawing from {start_point[0]} to {end_point[0]}') + for ly in range(start_point[1], end_point[1]+1): + g[ly][lx] += 1 + + +def draw_diagonal(g, dline): + x1 = dline[0][0] + y1 = dline[0][1] + x2 = dline[1][0] + y2 = dline[1][1] + + hdir = 1 + if x1 > x2: + hdir = -1 + + vdir = 1 + if y1 > y2: + vdir = -1 + + lx = x1 + ly = y1 + for i in range(abs(x2-x1)+1): + g[ly][lx] += 1 + lx += hdir + ly += vdir + + +hlines, vlines, dlines = parse_file('input.txt') +print(f'horizontal lines parsed: {len(hlines)}') +print(f'vertical lines parsed: {len(vlines)}') +print(f'diagonal lines parsed: {len(dlines)}') + +# detect size of the grid (assumed 1000x1000, but why not ;-) ) +maxx = 0 +maxy = 0 +for line in hlines + vlines + dlines: + startp = line[0] + endp = line[1] + if startp[0] > maxx: + maxx = startp[0] + if endp[0] > maxx: + maxx = endp[0] + if startp[1] > maxy: + maxy = startp[1] + if endp[1] > maxy: + maxy = endp[1] + +print(f'detected grid size: {maxx} x {maxy}') +grid = [[0] * (maxx+1) for _ in range(maxy+1)] + +# draw +for hl in hlines: + draw_horizontal(grid, hl) + +for vl in vlines: + draw_vertical(grid, vl) + +for dl in dlines: + draw_diagonal(grid, dl) + +# count points +points = 0 +for y in range(maxy+1): + for x in range(maxx+1): + if grid[y][x] > 1: + points += 1 + +print(f'There\'s {points} points with at least two lines') + +# bonus (or debug with the sample), draw the grid +# print(' ', end='') +# for y in range(maxy+1): +# print(y, end='') +# print() +# +# for y in range(maxy+1): +# print(f'{y} ', end='') +# for x in range(maxx+1): +# if grid[y][x] == 0: +# print('.', end='') +# else: +# print(str(grid[y][x]), end='') +# print()