foo.cc: In function 'void bfs(int, std::vector<int>, int)':
foo.cc:27:12: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
27 | if(step==M.size()&&a[0]!=0&&Sum(a,M.size())%k==0)
| ~~~~^~~~~~~~~~
foo.cc:34:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
34 | for(int i=0;i<M.size();i++)
| ~^~~~~~~~~
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