Compilare: user.cpp: In function ‘int main()’: user.cpp:93:25: warning: converting to non-pointer type ‘char’ from NULL [-Wconversion-null] sir [ ++ cate ] = NULL ; ^ user.cpp:124:25: warning: converting to non-pointer type ‘char’ from NULL [-Wconversion-null] sir [ ++ cate ] = NULL ; ^ user.cpp: In function ‘int cauta(int, char*, int, int)’: user.cpp:72:1: warning: control reaches end of non-void function [-Wreturn-type] } ^