Compilare: user.cpp: In function ‘void structura()’: user.cpp:39:7: warning: converting to non-pointer type ‘char’ from NULL [-Wconversion-null] *p=NULL; ^ user.cpp: In function ‘void fisier()’: user.cpp:66:25: warning: suggest parentheses around ‘&&’ within ‘||’ [-Wparentheses] for(i=poz;s[i]>='a' && s[i]<='z' || s[i]<='9' && s[i]>='0';i++) ^ user.cpp:68:14: warning: converting to non-pointer type ‘char’ from NULL [-Wconversion-null] nf[i-poz]=NULL; ^