Compilare: user.cpp: In function ‘void apm()’: user.cpp:46:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<v[1].size(); i++) ^ user.cpp:71:39: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<v[act.to].size(); i++) ^ user.cpp: In function ‘int dfs(int, int)’: user.cpp:92:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<ap[nod].size(); i++) ^ user.cpp: In function ‘int main()’: user.cpp:150:42: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<ap[amax].size(); i++) ^ user.cpp:159:42: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<ap[bmax].size(); i++) ^ user.cpp:115:32: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("online.in","r",stdin); ^ user.cpp:116:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("online.out","w",stdout); ^