Compilare: user.cpp: In function ‘int main()’: user.cpp:19:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while (i<strlen(t)) ^ user.cpp:28:43: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while (t[i]!=' ' && i<strlen(t) && t[i]!=')' && t[i]!='(') ^