foo.cc: In function ‘bool check()’:
foo.cc:53:29: warning: comparison of integer expressions of different signedness: ‘int’ and ‘std::vector<int>::size_type’ {aka ‘long unsigned int’} [-Wsign-compare]
   53 |                         if(l==line[i].size())
      |                            ~^~~~~~~~~~~~~~~~
foo.cc:71:29: warning: comparison of integer expressions of different signedness: ‘int’ and ‘std::vector<int>::size_type’ {aka ‘long unsigned int’} [-Wsign-compare]
   71 |                         if(l==list[j].size())
      |                            ~^~~~~~~~~~~~~~~~
foo.cc: In function ‘void dfs(int, int)’:
foo.cc:115:9: warning: this ‘if’ clause does not guard... [-Wmisleading-indentation]
  115 |         if(n-x<slist[y]-havelist[y]-2)
      |         ^~
foo.cc:117:17: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the ‘if’
  117 |                 a[x][y]=1;
      |                 ^