chessboard.cpp: In function 'int main()':
chessboard.cpp:30:21: warning: format '%d' expects argument of type 'int', but argument 2 has type 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wformat=]
   30 |  if(debug) printf("%d, g%d\n",factor.size(),g);//
      |                    ~^         ~~~~~~~~~~~~~
      |                     |                    |
      |                     int                  std::vector<int>::size_type {aka long unsigned int}
      |                    %ld
chessboard.cpp:35:16: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   35 |   for(int i=0;i<factor.size();i++)
      |               ~^~~~~~~~~~~~~~
chessboard.cpp:54:15: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   54 |  for(int i=0;i<factor.size();i++)
      |              ~^~~~~~~~~~~~~~
chessboard.cpp:18:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   18 |  scanf("%d %d",&N,&K);
      |  ~~~~~^~~~~~~~~~~~~~~
chessboard.cpp:33:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   33 |   scanf("%d %d %d %d",&x1,&y1,&x2,&y2);
      |   ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~