Compilare: user.cpp: In function ‘int main()’: user.cpp:2:100: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] using namespace std;int n,v[1000007],q[1000007],s=-1,i;int main(){freopen("mincinosi.in","r",stdin);freopen("mincinosi.out","w",stdout);scanf("%d",&n);for(i=1;i<=n;i++){scanf("%d",&v[i]);q[v[i]]++;}for(i=0;i<=n;i++)if((i+q[i])==n){s=i;break;}printf("%d\n",q[s]);for(i=1;i<=n;i++)if(v[i]==s)printf("%d\n",i);} ^ user.cpp:2:136: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] using namespace std;int n,v[1000007],q[1000007],s=-1,i;int main(){freopen("mincinosi.in","r",stdin);freopen("mincinosi.out","w",stdout);scanf("%d",&n);for(i=1;i<=n;i++){scanf("%d",&v[i]);q[v[i]]++;}for(i=0;i<=n;i++)if((i+q[i])==n){s=i;break;}printf("%d\n",q[s]);for(i=1;i<=n;i++)if(v[i]==s)printf("%d\n",i);} ^ user.cpp:2:151: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] using namespace std;int n,v[1000007],q[1000007],s=-1,i;int main(){freopen("mincinosi.in","r",stdin);freopen("mincinosi.out","w",stdout);scanf("%d",&n);for(i=1;i<=n;i++){scanf("%d",&v[i]);q[v[i]]++;}for(i=0;i<=n;i++)if((i+q[i])==n){s=i;break;}printf("%d\n",q[s]);for(i=1;i<=n;i++)if(v[i]==s)printf("%d\n",i);} ^ user.cpp:2:187: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] using namespace std;int n,v[1000007],q[1000007],s=-1,i;int main(){freopen("mincinosi.in","r",stdin);freopen("mincinosi.out","w",stdout);scanf("%d",&n);for(i=1;i<=n;i++){scanf("%d",&v[i]);q[v[i]]++;}for(i=0;i<=n;i++)if((i+q[i])==n){s=i;break;}printf("%d\n",q[s]);for(i=1;i<=n;i++)if(v[i]==s)printf("%d\n",i);} ^