Compilare: main.cpp: In function 'int main()': main.cpp:202:37: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("arbint.in", "r", stdin); ^ main.cpp:203:39: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("arbint.out", "w", stdout); ^ main.cpp: In function 'char getChar()': main.cpp:155:41: 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, kBuffSize, stdin); ^ main.cpp: In member function 'Tinfo SegmentTree<Tinfo, Combiner>::query(int, int) [with Tinfo = int; Combiner = myCombiner<int>]': main.cpp:106:11: warning: 'retl' may be used uninitialized in this function [-Wmaybe-uninitialized] Tinfo retl, retr; ^~~~ main.cpp:106:17: warning: 'retr' may be used uninitialized in this function [-Wmaybe-uninitialized] Tinfo retl, retr; ^~~~