Changing the way arrows appear on a MT4 indicator

The below code is supposed to show an arrow for every four candles depending on the close price.

My problem is that I want just one arrow to appear a time, but arrows keep showing as long as the price keep falling or raising.

And how to change the rule from closing price to falling or raising candles?

Thank you.

extern string arr_set="Arrow settings";
extern int arrow_indent=22;
extern int up_arrow_code=233;
extern int down_arrow_code=234;

extern string emp1="///////////////////////////////////////";
extern string al_set="Alerts settings";
extern bool use_alert=false;
extern string up_alert="UP";
extern string down_alert="DOWN";

double up_arr[];
double down_arr[];
int prev_bars;
/////////////////////////////////////////////////////////////////
int OnInit()
  {
   SetIndexBuffer(0,up_arr);
   SetIndexStyle(0,DRAW_ARROW);
   SetIndexArrow(0,up_arrow_code);
   SetIndexLabel(0,"UP arrow");

   SetIndexBuffer(1,down_arr);
   SetIndexStyle(1,DRAW_ARROW);
   SetIndexArrow(1,down_arrow_code);
   SetIndexLabel(1,"DOWN arrow");

   return(INIT_SUCCEEDED);
  }
//////////////////////////////////////////////////////////////////
int OnCalculate(const int rates_total,const int prev_calculated,const datetime &time[],const double &open[],const double &high[],
                const double &low[],const double &close[],const long &tick_volume[],const long &volume[],const int &spread[])
  {
//no bars
   if(Bars<20) return(rates_total);

//history update
   int all=rates_total;
   int counted=prev_calculated;
   if(all-counted>1)
     {
      ArrayInitialize(up_arr,EMPTY_VALUE);
      ArrayInitialize(down_arr,EMPTY_VALUE);
      counted=0;
     }

//main
   for(int i=all-counted;i>=0;i--)
     {
      if(i>Bars-20) i=Bars-20;

      if(i==0)
        {
         up_arr[i]=EMPTY_VALUE;
         down_arr[i]=EMPTY_VALUE;
        }

      if(Close[i]>Close[i+1] && Close[i+1]>Close[i+2] && Close[i+2]>Close[i+3] && Close[i+3]>Close[i+4]) up_arr[i]=Low[i]-arrow_indent*Point; //up arrow
      if(Close[i]<Close[i+1] && Close[i+1]<Close[i+2] && Close[i+2]<Close[i+3] && Close[i+3]<Close[i+4]) down_arr[i]=High[i]+arrow_indent*Point; //down arrow
     }

//new bar
   if(Bars==prev_bars) return(rates_total);
   prev_bars=Bars;

//Alerts
   if(use_alert)
     {
      if(up_arr[1]!=EMPTY_VALUE) Alert(Symbol()," ",Period()," ",up_alert);
      if(down_arr[1]!=EMPTY_VALUE) Alert(Symbol()," ",Period()," ",down_alert);
     }

   return(rates_total);
  }
//+------------------------------------------------------------------+