foo.cc: In function 'void dts::dfs(std::vector<long long int>)':
foo.cc:24:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
for (ll i=0;i<rec.size();i++)
~^~~~~~~~~~~
foo.cc:25:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
for (ll j=i+1;j<rec.size();j++)
~^~~~~~~~~~~
foo.cc:27:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
for (ll k=0,l=0;k<rec.size();k++)
~^~~~~~~~~~~
foo.cc: In function 'void dts::main()':
foo.cc:63:9: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
scanf("%s",s);
~~~~~^~~~~~~~