Compilare: user.cpp: In function ‘int main()’: user.cpp:31:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<S.length();i++) ~^~~~~~~~~~~ user.cpp:33:16: warning: array subscript has type ‘char’ [-Wchar-subscripts] nS[S[i]][0]++; ^ user.cpp:34:22: warning: array subscript has type ‘char’ [-Wchar-subscripts] nS[caps(S[i])][1]++; ^ user.cpp:50:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=1;i<=l;i++) ~^~~ user.cpp:49:13: warning: unused variable ‘nr’ [-Wunused-variable] int nr=0; ^~ user.cpp: In function ‘char caps(char)’: user.cpp:22:12: warning: ‘ch’ may be used uninitialized in this function [-Wmaybe-uninitialized] return ch; ^~ user.cpp: In function ‘int main()’: user.cpp:18:10: warning: ‘ch’ may be used uninitialized in this function [-Wmaybe-uninitialized] char ch; ^~