Compilare: user.cpp: In function ‘void read()’: user.cpp:78:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("sir3.in", "r", stdin); ^ user.cpp: In function ‘void cit(int&)’: user.cpp:22:46: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread (ax, 1, dim, stdin), pz = 0; ^ user.cpp:28:46: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread (ax, 1, dim, stdin), pz = 0; ^ user.cpp: In function ‘void solve()’: user.cpp:136:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("sir3.out", "w", stdout); ^