Compilare: user.cpp: In function ‘int main()’: user.cpp:109:12: warning: unused variable ‘b’ [-Wunused-variable] int a, b; ^ user.cpp: In function ‘void read(int&)’: user.cpp:89:38: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(buff,1,chMax,stdin); ^ user.cpp:98:38: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(buff,1,chMax,stdin); ^ user.cpp: In function ‘int main()’: user.cpp:106:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("arb.in", "r", stdin); ^ user.cpp:107:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("arb.out", "w", stdout); ^ user.cpp:108:33: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(buff, 1, chMax, stdin); ^