Funzione n84 slide4b

# Problema slide4b n84

def swapColumn(pict, numCol):
# @param pict: Picture
# @param numCol: Int. Numero delle colonne
  columnWidth = getWidth(pict)/numCol
  for i in range(0, getWidth(pict), 2*columnWidth):
    for x in range(i, min(getWidth(pict), i+columnWidth)):
      for y in range(getHeight(pict)):
        pixelColA = getPixel(pict, x, y)
        pixelColB = getPixel(pict, min(getWidth(pict)-1, x+columnWidth), y)
        colorA = getColor(pixelColA)
        colorB = getColor(pixelColB)
        setColor(pixelColA, colorB)
        setColor(pixelColB, colorA)