Compilare: user.cpp: In function ‘int get_number()’: user.cpp:11:13: warning: suggest parentheses around comparison in operand of ‘|’ [-Wparentheses] for(; c < 48 | c > 57; c = getchar()); ~~^~~~ user.cpp:13:13: warning: suggest parentheses around comparison in operand of ‘&’ [-Wparentheses] for(; c > 47 & c < 58; nr = nr * 10 + c - 48, c = getchar()); ~~^~~~ user.cpp: At global scope: user.cpp:20:37: warning: always_inline function might not be inlinable [-Wattributes] __attribute__((always_inline)) void put_int(int x) ^~~~~~~ user.cpp:7:36: warning: always_inline function might not be inlinable [-Wattributes] __attribute__((always_inline)) int get_number() ^~~~~~~~~~ user.cpp: In function ‘int main()’: user.cpp:55:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("cautbin.in", "r", stdin); ^ user.cpp:56:40: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("cautbin.out", "w", stdout); ^ user.cpp:58:41: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(buffer, 1, BUFFER_SIZE, stdin); ^