/in/foo.cc: In function 'long long int vv2(long long int, long long int)':
/in/foo.cc:34:1: warning: control reaches end of non-void function [-Wreturn-type]
 }
 ^
/in/foo.cc: In function 'void vv1(long long int, long long int)':
/in/foo.cc:24:33: warning: array subscript is below array bounds [-Warray-bounds]
  if(xx<0 && yy>=0) vist[1][0][xx][yy]=1;
                    ~~~~~~~~~~~~~^
/in/foo.cc:25:37: warning: array subscript is below array bounds [-Warray-bounds]
  if(xx>=0 && yy<0) vist[0][1][xx][yy]=1;
                    ~~~~~~~~~~~~~~~~~^
/in/foo.cc:26:36: warning: array subscript is below array bounds [-Warray-bounds]
  if(xx<0 && yy<0) vist[1][1][xx][yy]=1;
                   ~~~~~~~~~~~~~~~~~^
/in/foo.cc:26:32: warning: array subscript is below array bounds [-Warray-bounds]
  if(xx<0 && yy<0) vist[1][1][xx][yy]=1;
                   ~~~~~~~~~~~~~^
/in/foo.cc: In function 'long long int vv2(long long int, long long int)':
/in/foo.cc:31:40: warning: array subscript is below array bounds [-Warray-bounds]
  if(xx<0 && yy>=0) return vist[1][0][xx][yy];
                           ~~~~~~~~~~~~~^
/in/foo.cc:32:44: warning: array subscript is below array bounds [-Warray-bounds]
  if(xx>=0 && yy<0) return vist[0][1][xx][yy];
                           ~~~~~~~~~~~~~~~~~^
/in/foo.cc:33:43: warning: array subscript is below array bounds [-Warray-bounds]
  if(xx<0 && yy<0) return vist[1][1][xx][yy];
                          ~~~~~~~~~~~~~~~~~^
/in/foo.cc:33:39: warning: array subscript is below array bounds [-Warray-bounds]
  if(xx<0 && yy<0) return vist[1][1][xx][yy];
                          ~~~~~~~~~~~~~^