Compilare: In file included from /usr/local/include/c++/4.8.0/ext/hash_map:60:0, from user.cpp:6: /usr/local/include/c++/4.8.0/backward/backward_warning.h:32:2: warning: #warning This file includes at least one deprecated or antiquated header which may be removed without further notice at a future date. Please use a non-deprecated interface with equivalent functionality instead. For a listing of replacement headers and interfaces, consult the file backward_warning.h. To disable this warning use -Wno-deprecated. [-Wcpp] #warning \ ^ user.cpp: In function ‘void findGoodPairing(int)’: user.cpp:30:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (j = 0; j < v[i].size(); j++) ^ user.cpp:41:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (j = 0; j < v[i].size(); j++) ^ user.cpp: In function ‘int main()’: user.cpp:129:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (j = 0; j < v[i].size(); j++) ^ user.cpp:162:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while (j < v[i].size()) ^