foo.cpp:16:6: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
foo.cpp: In function 'int main()':
foo.cpp:18:20: error: 'scanf' was not declared in this scope
foo.cpp:20:21: error: 'memset' was not declared in this scope
foo.cpp:41:43: error: 'printf' was not declared in this scope