0123456789 --- --- 0*4 1*5 2*6 1*5 2*6 = L + 3*7 - 0*4 3*7 2*6 3*7 = L + 4*8 - 1*5 4*8 3*7 4*8 = L + 5*9 - 2*6 5*9 0*5 1*6 2*7 1*6 2*7 3*8 2*7 3*8 4*9 => Use same technique to cache the interpolation results