Compilare: user.cpp: In function ‘void Read_Input()’: user.cpp:21:15: warning: unused variable ‘a’ [-Wunused-variable] long long a,b; ^ user.cpp:21:17: warning: unused variable ‘b’ [-Wunused-variable] long long a,b; ^ user.cpp:20:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&N,&K); ^ user.cpp:23:53: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&node[i].first,&node[i].second); ^ user.cpp: In function ‘int main()’: user.cpp:83:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("banana.in","r",stdin); ^ user.cpp:84:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("banana.out","w",stdout); ^