Compilare: main.cpp: In function 'int main()': main.cpp:3:82: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] const int NMax=500002;char v[NMax];int main(){freopen("staropramen.in","r",stdin);freopen("staropramen.out","w",stdout);int t,n,m,aux;char a,b;scanf("%d",&t);while(t--){m=0;scanf("%d %c %c",&n,&a,&b); ^ main.cpp:3:120: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] const int NMax=500002;char v[NMax];int main(){freopen("staropramen.in","r",stdin);freopen("staropramen.out","w",stdout);int t,n,m,aux;char a,b;scanf("%d",&t);while(t--){m=0;scanf("%d %c %c",&n,&a,&b); ^ main.cpp:3:158: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] const int NMax=500002;char v[NMax];int main(){freopen("staropramen.in","r",stdin);freopen("staropramen.out","w",stdout);int t,n,m,aux;char a,b;scanf("%d",&t);while(t--){m=0;scanf("%d %c %c",&n,&a,&b); ^ main.cpp:3:200: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] const int NMax=500002;char v[NMax];int main(){freopen("staropramen.in","r",stdin);freopen("staropramen.out","w",stdout);int t,n,m,aux;char a,b;scanf("%d",&t);while(t--){m=0;scanf("%d %c %c",&n,&a,&b); ^ main.cpp:13:21: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%c %c",&a,&b); ^