double b;
            double[] a = new double[4] { -3, 0, 0, 5 };
            b = a[3] - a[0];
            a[1] = a[3] - 0.618 * b;
            a[2] = a[0] + 0.618 * b;
                while (System.Math.Abs((a[1] * a[1] + 2 * a[1]) - (a[2] * a[2] + 2 * a[2])) > 0.01)
                {
                    if ((a[1] * a[1] + 2 * a[1]) < (a[2] * a[2] + 2 * a[2]))
                    {
                        a[3] = a[2];
                        b = a[3] - a[0];
                        a[1] = a[3] - 0.618 * b;
                        a[2] = a[0] + 0.618 * b;
                    }
                    else if ((a[1] * a[1] + 2 * a[1]) < (a[2] * a[2] + 2 * a[2]))
                    {
                        a[0] = a[1];
                        b = a[3] - a[0];
                        a[1] = a[3] - 0.618 * b;
                        a[2] = a[0] + 0.618 * b;
                    }
                }

恩恩，我就想依据while条件，求出最后的数组，但为什么循环不了啊？求指教！！！1

哥，题目是这样的：对函数f=a*a+2*a，给定搜索区间-3<=a<=5时，使用黄金分割法求极小点。