Perform mouse click in C++

#include <windows.h>

// Forward declaration of the LeftClick function
void LeftClick ( );

// Forward declaration of the MouseMove function
void MouseMove ( int x, int y );

int main()
{
    MouseMove(530, 1);
    LeftClick();
    MouseMove(530, 350);
    LeftClick();
    return 0;
}

// LeftClick function
void LeftClick ( )
{
  INPUT    Input={0};
  // left down
  Input.type      = INPUT_MOUSE;
  Input.mi.dwFlags  = MOUSEEVENTF_LEFTDOWN;
  ::SendInput(1,&Input,sizeof(INPUT));

  // left up
  ::ZeroMemory(&Input,sizeof(INPUT));
  Input.type      = INPUT_MOUSE;
  Input.mi.dwFlags  = MOUSEEVENTF_LEFTUP;
  ::SendInput(1,&Input,sizeof(INPUT));
}

// MouseMove function
void MouseMove (int x, int y )
{
    double fScreenWidth    = ::GetSystemMetrics( SM_CXSCREEN )-1;
    double fScreenHeight  = ::GetSystemMetrics( SM_CYSCREEN )-1;
    double fx = x*(65535.0f/fScreenWidth);
    double fy = y*(65535.0f/fScreenHeight);
    INPUT  Input={0};
    Input.type      = INPUT_MOUSE;
    Input.mi.dwFlags  = MOUSEEVENTF_MOVE|MOUSEEVENTF_ABSOLUTE;
    Input.mi.dx = fx;
    Input.mi.dy = fy;
    ::SendInput(1,&Input,sizeof(INPUT));
}