tunel.cpp: In function `void scade(int&)': tunel.cpp:6: warning: NULL used in arithmetic tunel.cpp: In function `int main()': tunel.cpp:15: warning: char format, different type arg (arg 2) tunel.cpp:17: warning: char format, different type arg (arg 2) tunel.cpp:26: warning: assignment to non-pointer type `char' from NULL tunel.cpp:26: warning: argument to non-pointer type `char' from NULL