Compilare: user.cpp: In function ‘int main()’: user.cpp:6:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("mincinosi.in","r",stdin);freopen("mincinosi.out","w",stdout);scanf("%d",&n);for(int i=1;i<=n;i++) {scanf("%d",&v1[i]);v2[v1[i]]++;}for(int i=0;i<=n;i++) if((i+v2[i])==n) {sol=i;ma=v2[i];break;}printf("%d\n",ma);for(int i=1;i<=n;i++) if(v1[i]==sol) printf("%d\n",i); ^ user.cpp:6:74: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("mincinosi.in","r",stdin);freopen("mincinosi.out","w",stdout);scanf("%d",&n);for(int i=1;i<=n;i++) {scanf("%d",&v1[i]);v2[v1[i]]++;}for(int i=0;i<=n;i++) if((i+v2[i])==n) {sol=i;ma=v2[i];break;}printf("%d\n",ma);for(int i=1;i<=n;i++) if(v1[i]==sol) printf("%d\n",i); ^ user.cpp:6:89: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] freopen("mincinosi.in","r",stdin);freopen("mincinosi.out","w",stdout);scanf("%d",&n);for(int i=1;i<=n;i++) {scanf("%d",&v1[i]);v2[v1[i]]++;}for(int i=0;i<=n;i++) if((i+v2[i])==n) {sol=i;ma=v2[i];break;}printf("%d\n",ma);for(int i=1;i<=n;i++) if(v1[i]==sol) printf("%d\n",i); ^ user.cpp:6:131: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] freopen("mincinosi.in","r",stdin);freopen("mincinosi.out","w",stdout);scanf("%d",&n);for(int i=1;i<=n;i++) {scanf("%d",&v1[i]);v2[v1[i]]++;}for(int i=0;i<=n;i++) if((i+v2[i])==n) {sol=i;ma=v2[i];break;}printf("%d\n",ma);for(int i=1;i<=n;i++) if(v1[i]==sol) printf("%d\n",i); ^