Compilare: user.cpp: In function ‘void read()’: user.cpp:49:9: warning: unused variable ‘var’ [-Wunused-variable] int var = ceil(log2(n)); ^ user.cpp:50:29: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d\n", &n, &m); ^ user.cpp:53:34: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d\n", &mat[i][0]); ^ user.cpp:60:33: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d\n", &x, &y); ^ user.cpp: In function ‘int main()’: user.cpp:66:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("rmq.in", "r", stdin); ^ user.cpp:67:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("rmq.out", "w", stdout); ^