Python Challenge[14]

[Level 14]

Title: walk around

这次有两张图片，第二张实际上是100001像素的图片。源码中有提示：remember: 100100 = (100+99+99+98) + (...。实在想不出来，搜索了知道是将第二张图片照第一张图螺旋地重新排列，提示信息括号中指的是从最外圈开始排列的每一圈步数。

from PIL import Image
img = Image.open('wire.png')
newImg = Image.new(img.mode,(100,100))
y, t, count =0, 0, 0
while t<10000:
  for x in range(0+count,100-count):
    newImg.putpixel((x,y),img.getpixel((t,0)))
    t = t + 1
  for y in range(0+count,99-count):
    newImg.putpixel((x,y),img.getpixel((t,0)))
    t = t + 1
  for x in range(99-count,0+count,-1):
    newImg.putpixel((x,y),img.getpixel((t,0)))
    t = t + 1
  for y in range(98-count,0+count,-1):
    newImg.putpixel((x,y),img.getpixel((t,0)))
    t = t + 1
  count=1+count
newImg.show()

得到一幅的图片，修改为cat.html，显示and its name is uzi. you'll hear from him later.，再次修改url，[Level 15]

小结

错误的排列可能会得到bit，bit.html提示you took the wrong curve.。使用getdata()和putdata()方法也可以达到同样效果。

Python Challenge Wiki

可以定义方向（或步骤），触发某个条件执行类似转向的操作，或者旋转，然后继续排列。

from PIL import Image
src = Image.open('wire.png')
dst = Image.new(src.mode, (100, 100))
x, y, idx = -1, 0, 0            # back a step
steps = [1,0, 0,1, -1,0, 0,-1]
while idx < 10000:
  nx, ny = x + steps[0], y + steps[1]
  if 0 <= nx < 100 and 0 <= ny < 100 \
  and dst.getpixel((nx, ny)) == (0, 0, 0):
    x, y = nx, ny
    dst.putpixel((x, y), src.getpixel((idx, 0)))
    idx += 1
  else:
    steps = steps[2:] + steps[:2] # turn
dst.show()

More