Compilare: user.cpp: In function ‘void verifica()’: user.cpp:12:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<strlen(c)/2;i++){ ^ user.cpp:13:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=0;j<strlen(c);j++) ^ user.cpp:10:9: warning: unused variable ‘contor’ [-Wunused-variable] int contor=0; ^ user.cpp: In function ‘int main()’: user.cpp:45:11: warning: unused variable ‘l’ [-Wunused-variable] int n,l; ^