请写出MT4的分型指标Fractals 源代码

以下是MT4 Fractals指标的源代码：

#property indicator_chart_window
#property indicator_buffers 2
#property indicator_color1 Red
#property indicator_color2 Lime

extern int BarsToCount = 2; // Fractal calculation period

double ExtMapBuffer1[];
double ExtMapBuffer2[];

void CalculateFractals(int shift)
{
    if (shift < BarsToCount) return;

    double hi = High[shift];
    double lo = Low[shift];

    bool fractal_high = true;
    bool fractal_low = true;

    for (int i = 1; i <= BarsToCount; i++)
    {
        if (High[shift - i] > hi)
        {
            fractal_high = false;
        }
        if (Low[shift - i] < lo)
        {
            fractal_low = false;
        }
    }

    if (fractal_high)
    {
        ExtMapBuffer1[shift - BarsToCount] = hi;
    }
    else
    {
        ExtMapBuffer1[shift - BarsToCount] = 0;
    }

    if (fractal_low)
    {
        ExtMapBuffer2[shift - BarsToCount] = lo;
    }
    else
    {
        ExtMapBuffer2[shift - BarsToCount] = 0;
    }
}

int init()
{
    SetIndexBuffer(0, ExtMapBuffer1, INDICATOR_DATA);
    SetIndexBuffer(1, ExtMapBuffer2, INDICATOR_DATA);

    return(0);
}

int start()
{
    int limit = Bars - BarsToCount - 1;

    for(int i = limit; i >= 0; i--)
    {
        CalculateFractals(i);
    }

    return(0);
}

这个指标使用`BarsToCount`参数来计算最近几个价格周期内的分型。如果最高价在指定周期内是极大值，那么就标记为顶部分型；如果最低价在指定周期内是极小值，那么就标记为底部分型。这些标记存储在两个指标缓冲区`ExtMapBuffer1`和`ExtMapBuffer2`中，分别用红色和绿色表示。