foo.cc: In function 'int bfs_1(int, int)':
foo.cc:34:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::vector<int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   34 |         for (int i=0;i<c.size();i++)
      |                      ~^~~~~~~~~
foo.cc: In function 'int main()':
foo.cc:65:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::vector<int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   65 |             for (int i=0;i<c.size();i++)
      |                          ~^~~~~~~~~
foo.cc:62:18: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   62 |             scanf("%d%d",&n,&m);
      |             ~~~~~^~~~~~~~~~~~~~
foo.cc:68:22: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   68 |                 scanf("%d",&c[n+1+i][i]);
      |                 ~~~~~^~~~~~~~~~~~~~~~~~~
foo.cc:72:22: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   72 |                 scanf("%d%d",&x,&y);
      |                 ~~~~~^~~~~~~~~~~~~~

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