Compilare: main.cpp: In function 'int main()': main.cpp:3:74: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] using namespace std;int v[3000005];int main(){freopen("sdo.in","r",stdin);freopen("sdo.out","w",stdout);int n,k;scanf("%d%d",&n,&k);for(int i=0;i<n;++i)scanf("%d",&v[i]);sort(v,+v+n);printf("%d",v[k-1]);return 0;} ^ main.cpp:3:104: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] using namespace std;int v[3000005];int main(){freopen("sdo.in","r",stdin);freopen("sdo.out","w",stdout);int n,k;scanf("%d%d",&n,&k);for(int i=0;i<n;++i)scanf("%d",&v[i]);sort(v,+v+n);printf("%d",v[k-1]);return 0;} ^ main.cpp:3:132: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] using namespace std;int v[3000005];int main(){freopen("sdo.in","r",stdin);freopen("sdo.out","w",stdout);int n,k;scanf("%d%d",&n,&k);for(int i=0;i<n;++i)scanf("%d",&v[i]);sort(v,+v+n);printf("%d",v[k-1]);return 0;} ^ main.cpp:3:170: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] using namespace std;int v[3000005];int main(){freopen("sdo.in","r",stdin);freopen("sdo.out","w",stdout);int n,k;scanf("%d%d",&n,&k);for(int i=0;i<n;++i)scanf("%d",&v[i]);sort(v,+v+n);printf("%d",v[k-1]);return 0;} ^