Compilare: main.cpp: In function 'int main()': main.cpp:48:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(unsigned long long i=1;i<=n;++i) ~^~~ main.cpp:64:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(len+1>s[1].size() || len+1>s[2].size() || (len+1>s[3].size() && s[3].size()!=0) || (len+1>s[4].size() && s[4].size()!=0) ) ~~~~~^~~~~~~~~~~~ main.cpp:64:38: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(len+1>s[1].size() || len+1>s[2].size() || (len+1>s[3].size() && s[3].size()!=0) || (len+1>s[4].size() && s[4].size()!=0) ) ~~~~~^~~~~~~~~~~~ main.cpp:64:60: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(len+1>s[1].size() || len+1>s[2].size() || (len+1>s[3].size() && s[3].size()!=0) || (len+1>s[4].size() && s[4].size()!=0) ) ~~~~~^~~~~~~~~~~~ main.cpp:64:102: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(len+1>s[1].size() || len+1>s[2].size() || (len+1>s[3].size() && s[3].size()!=0) || (len+1>s[4].size() && s[4].size()!=0) ) ~~~~~^~~~~~~~~~~~ main.cpp:80:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(j>len) ~^~~~