Compilare: user.cpp: In function ‘int bfs()’: user.cpp:44:42: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0 ; i < v[virf].size() ; ++i){ ^ user.cpp: In function ‘void max_flow()’: user.cpp:61:39: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0 ; i < v[N].size() ; ++i){ ^ user.cpp: In function ‘void bfs2(int, int*)’: user.cpp:86:42: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0 ; i < v[virf].size() ; ++i){ ^ user.cpp: In function ‘void solve()’: user.cpp:102:39: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j = 0 ; j < v[i].size() ; ++j) ^ user.cpp:108:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0 ;i < sol.size() ;++i) ^