Compilare: user.cpp: In function ‘bool ok(int)’: user.cpp:20:13: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(rep-1>=who[b[0]-'a'].size()) return 0; ~~~~~^~~~~~~~~~~~~~~~~~~~~~ user.cpp:23:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=1;i<b.size();i++) ~^~~~~~~~~ user.cpp:29:28: warning: array subscript has type ‘char’ [-Wchar-subscripts] if(r+pas<who[ch].size() && who[ch][r+pas]<=poz) r+=pas; ^ user.cpp:29:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(r+pas<who[ch].size() && who[ch][r+pas]<=poz) r+=pas; ~~~~~^~~~~~~~~~~~~~~ user.cpp:29:46: warning: array subscript has type ‘char’ [-Wchar-subscripts] if(r+pas<who[ch].size() && who[ch][r+pas]<=poz) r+=pas; ^ user.cpp:36:28: warning: array subscript has type ‘char’ [-Wchar-subscripts] if(0<=r && r<who[ch].size()) ^ user.cpp:36:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(0<=r && r<who[ch].size()) ~^~~~~~~~~~~~~~~ user.cpp:38:23: warning: array subscript has type ‘char’ [-Wchar-subscripts] poz=who[ch][r]; ^