Compilare: user.cpp: In function ‘int query_tree(int, int, int, int, int)’: user.cpp:121:9: warning: unused variable ‘p2’ [-Wunused-variable] int p2=node*2+1; ^ user.cpp: In function ‘int main()’: user.cpp:134:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("biscuiti.in","r",stdin); ^ user.cpp:135:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("biscuiti.out","w",stdout); ^ user.cpp:136:21: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%lld",&N); ^ user.cpp:137:80: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] for(int i = 0; i < N; i++)scanf("%lld",&arr[i]),ma=max(arr[i],ma),S+=arr[i]; ^