Compilare: user.cpp: In function ‘int query(int, int, int, int, int, int, int)’: user.cpp:99:9: warning: unused variable ‘cate’ [-Wunused-variable] int cate = 0, mid = (lo + hi) >> 1; ^ user.cpp: In function ‘char getChar()’: user.cpp:24:28: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(buf, 1, DIM, stdin); ^ user.cpp: In function ‘int main()’: user.cpp:120:31: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("zoo.in", "r", stdin); ^ user.cpp:121:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("zoo.out", "w", stdout); ^ user.cpp:123:27: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(buf, 1, DIM, stdin); ^