Hi guys:

I was stucked in a problem, the program can be built and run for a about 19 minutes, and then exited with code -1073740940.
I don't know where can find the code means ?
Develop environment : Qt 5.14.0 / Windows 10

After checked my code and did a lot of test , I found that when I disable some code sections, it would run for a long time.
The function was reading a block of dem data from memory, and it runs a about 60 times per second.

Qt Code: 
  1. short int* DemPreLoad::LoadDemData_Area()
  2.   {
  3.         short int* crop = (short int*)malloc(sizeof(short int) * _Terrian_Range * _Terrian_Range*4);           // _Terrian_Range is const for 100
  4.         Location location = getLocation();                                  // According to longtitude & latitude caculate which row & col the right data in the dem data map
  5.         Location beginlocation;
  6.         int beginIndex;
  7.  
  8.         beginlocation.col = location.col - _Terrian_Range;
  9.         beginlocation.row = location.row - _Terrian_Range;
  10.         beginIndex = (int)(beginlocation.col + beginlocation.row * 43200);
  11.  
  12.         for (int rows = 0; rows < _Terrian_Range * 2; rows++)
  13.          {
  14.             for (int cols = 0; cols < _Terrian_Range * 2; cols++)
  15.              {
  16.                 crop[cols + rows * _Terrian_Range*2] = _DataNow[beginIndex + cols];
  17.                 if (demlow>_DataNow[beginIndex + cols]) demlow=_DataNow[beginIndex + cols];
  18.                 if (demhigh<_DataNow[beginIndex + cols]) demhigh=_DataNow[beginIndex + cols];
  19.              }
  20.               beginIndex += 43200;
  21.            }
  22.  
  23.         return crop;
  24.   }
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My questions are :
1? Where could I find the code means.
2? How could fix the problem(s).

Thanks a lot.