void gotoxy(int x, int y) {
    // printf("\033[%d;%dH", y, x);
    COORD V={x, y};
    SetConsoleCursorPosition(GetStdHandle(STD_OUTPUT_HANDLE), V);
}

void clrscr() 
{ 
	//Clear Screen
	// Refer:
	//   https://zhuanlan.zhihu.com/p/415237147
    HANDLE hdout = GetStdHandle(STD_OUTPUT_HANDLE);  // Get standard output handler
    CONSOLE_SCREEN_BUFFER_INFO csbi;    // Define screen buffer attribute variable
    GetConsoleScreenBufferInfo(hdout, &csbi);  // Get screen buffer attribute variable
    DWORD size = csbi.dwSize.X * csbi.dwSize.Y, num = 0; // Define screen size
    COORD pos = {0, 0}; // initial left-top (0,0) coordinate
    // Fill the window as ' ' space to clear the buffer
    FillConsoleOutputCharacter(hdout, ' ', size, pos, &num);
    FillConsoleOutputAttribute (hdout, csbi.wAttributes, size, pos, &num );
    SetConsoleCursorPosition(hdout, pos); // Set cursor to (0,0)
}