> 7.0 -5.0 -1.0 1.0 0.0 -6.0
> (x - 3.000)^2 + (y + 2.000)^2 = 5.000^2
> x^2 + y^2 - 6.000x + 4.000y - 12.000 = 0
> 
> 1.0 7.0 8.0 6.0 7.0 -2.0
> (x - 3.921)^2 + (y - 2.447)^2 = 5.409^2
> x^2 + y^2 - 7.842x - 4.895y - 7.895 = 0
> 
> 1 -1 0 0 -1 -1
> x^2 + (y + 1.000)^2 = 1.000^2
> x^2 + y^2 + 2.000y = 0
> 
> 1 -1 1 1 -1 1
> x^2 + y^2 = 1.414^2
> x^2 + y^2 - 2.000 = 0
> 
> -1 1 0 0 -1 -1
> (x + 1.000)^2 + y^2 = 1.000^2
> x^2 + y^2 + 2.000x = 0
> 
> -1 1 0 0 -1 -1
> (x + 1.000)^2 + y^2 = 1.000^2
> x^2 + y^2 + 2.000x = 0
> 
> -1 1 -1 -1 0 0
> (x + 1.000)^2 + y^2 = 1.000^2
> x^2 + y^2 + 2.000x = 0
> 
> 那些系数为0的要输出吗？