Compilare: user.cpp: In function ‘void cit(int&)’: user.cpp:19: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result user.cpp:24: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result user.cpp: In function ‘int main()’: user.cpp:32: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:49: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:69: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result In file included from /usr/include/string.h:640, from /usr/include/c++/4.4/cstring:45, from user.cpp:4: In function ‘void* memset(void*, int, size_t)’, inlined from ‘int main()’ at user.cpp:47: /usr/include/bits/string3.h:86: warning: call to void* __builtin___memset_chk(void*, int, unsigned int, unsigned int) will always overflow destination buffer