Compilare: user.cpp: In function ‘int main()’: user.cpp:26:9: warning: unused variable ‘j’ [-Wunused-variable] int n,i,j,pp=0; ^ user.cpp:26:11: warning: unused variable ‘pp’ [-Wunused-variable] int n,i,j,pp=0; ^ user.cpp:23:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("heavymetal.in","r",stdin); ^ user.cpp:24:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("heavymetal.out","w",stdout); ^ user.cpp:28:16: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%d",&n); ^ user.cpp:31:37: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%d%d",&v[i].st,&v[i].dr); ^