How can I populate a dynamic two dimensional array in a for loop

[BluePipsOnly]

This might seem trivial to many but I'm quite new to MQL5 and haven't been able to figure out how to use ArrayFill() to populate a two-dimensional array.

 In the code below I want to populate ar[][2] when isBody is true. How can I achieve this.

int ar[][2];

void CheckBody()   {

   for (int i = 20; i <= 0; i--) {
   
      if (isBody) {
         int a = i + 1;
         int b = i - 3*i;
         
         // how to populate ar with [a,b] when isBody is true in this block
         
      }
   }
}

[Vladimir Karputov]

Code:

//+------------------------------------------------------------------+
//|                                                     Script 1.mq5 |
//|                        Copyright 2020, MetaQuotes Software Corp. |
//|                                             https://www.mql5.com |
//+------------------------------------------------------------------+
#property copyright "Copyright 2020, MetaQuotes Software Corp."
#property link      "https://www.mql5.com"
#property version   "1.00"
//---
//+------------------------------------------------------------------+
//| Script program start function                                    |
//+------------------------------------------------------------------+
void OnStart()
  {
   int array_body[][2];
   bool is_body=true;
   CheckBody(is_body,array_body,10);
  }
//+------------------------------------------------------------------+
//| Check Body                                                       |
//+------------------------------------------------------------------+
void CheckBody(bool body,int &array[][],int size)
  {
   if(!body)
      return;
   int result=ArrayResize(array,size);
   if(result!=size)
     {
      Print("ERROR: size(",IntegerToString(size),") != result(",IntegerToString(result),")");
      return;
     }
   for(int i=0; i<size; i++)
     {
      array[i][0]=i+1;
      array[i][1]=i-3*i;
     }
//---
   ArrayPrint(array);
  }
//+------------------------------------------------------------------+

Result:

            [,0][,1]
        [0,]   1   0
        [1,]   2  -2
        [2,]   3  -4
        [3,]   4  -6
        [4,]   5  -8
        [5,]   6 -10
        [6,]   7 -12
        [7,]   8 -14
        [8,]   9 -16
        [9,]  10 -18

[BluePipsOnly]

Vladimir Karputov:

Code:

Result:

Thanks, this really helps. I would really like to know if there is a way to populate the array in the code I provided without having to restructure it.