Compilare: user.cpp: In function ‘int main()’: user.cpp:23:32: warning: passing NULL to non-pointer argument 2 of ‘void* memset(void*, int, size_t)’ [-Wconversion-null] memset(aux.y,NULL,m); ^ user.cpp:25:28: warning: suggest parentheses around ‘&&’ within ‘||’ [-Wparentheses] while(a[i]>='a'&&a[i]<='z'||a[i]>='0'&&a[i]<='9') ^ user.cpp:43:44: warning: suggest parentheses around ‘&&’ within ‘||’ [-Wparentheses] while(a[j]>='A'&&a[j]<='Z'||a[j]>='0'&&a[j]<='9') ^