Compilare: user.cpp: In function ‘void tarjan(int)’: user.cpp:25:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<v[x].size();++i) { ^ user.cpp: In function ‘int main()’: user.cpp:68:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=0;j<v[i].size();++j) { ^ user.cpp:76:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<res.size();++i) { ^ user.cpp:83:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<Y.size()-1;++i) ^ user.cpp:85:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(;i<X.size();++i) ^ user.cpp:88:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<X.size();++i) ^ user.cpp:92:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=X.size()+1;i<Y.size();++i) ^