Compilare: user.cpp: In function ‘void build(long long int, long long int)’: user.cpp:9:7: warning: suggest explicit braces to avoid ambiguous ‘else’ [-Wparentheses] if(st<dr) ^ user.cpp: In function ‘int main()’: user.cpp:64:29: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("maxq.in","r",stdin); ^ user.cpp:65:31: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("maxq.out","w",stdout); ^ user.cpp:66:17: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%lld",&n); ^ user.cpp:68:25: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%lld",&vc[i]); ^ user.cpp:77:17: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%lld",&q); ^ user.cpp:81:35: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%lld%lld%lld",&x,&y,&z); ^