Compilare: user.cpp: In function ‘int nrap(int)’: user.cpp:13:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(p==nullptr||i1>strlen(b+1)) ~~^~~~~~~~~~~~ user.cpp: In function ‘int main()’: user.cpp:21:9: warning: unused variable ‘n’ [-Wunused-variable] int n,i; ^ user.cpp:21:11: warning: unused variable ‘i’ [-Wunused-variable] int n,i; ^