Compilare: user.cpp: In function ‘int main()’: user.cpp:90:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(unsigned int i = 1; i <= N; ++i) ~~^~~~ user.cpp:114:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(unsigned int i = 1; i <= N; ++i) ~~^~~~ user.cpp: At global scope: user.cpp:53:37: warning: always_inline function might not be inlinable [-Wattributes] __attribute__((always_inline)) void put_int(int x) ^~~~~~~ user.cpp:41:36: warning: always_inline function might not be inlinable [-Wattributes] __attribute__((always_inline)) int get_int() ^~~~~~~ user.cpp: In function ‘int main()’: user.cpp:77:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("bfs.in", "r", stdin); ^ user.cpp:79:38: 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, 12500000, stdin); ^ user.cpp:110:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("bfs.out", "w", stdout); ^