Compilare: user.cpp: In function ‘int main()’: user.cpp:32:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<s.size();i++) g<<s[i]<<' '; ^ user.cpp:8:12: warning: unused variable ‘k’ [-Wunused-variable] int n, m, k=0; ^ user.cpp:15:6: warning: unused variable ‘len’ [-Wunused-variable] int len=0, i=1, j, q=0; ^ user.cpp:15:21: warning: unused variable ‘q’ [-Wunused-variable] int len=0, i=1, j, q=0; ^