Compilare: user.cpp: In function ‘int main()’: user.cpp:82:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < gv.size(); ++i){ ^ user.cpp:98:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = start; i < gv.size(); ++i){ ^ In file included from /usr/local/include/c++/4.8.0/cassert:43:0, from user.cpp:5: user.cpp:130:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] assert(ans.size() == n - 1); ^ user.cpp:131:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < ans.size(); ++i) ^ user.cpp:134:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < ans.size(); ++i) ^