Compilare: main.cpp: In function 'int main()': main.cpp:2:116: warning: operation on 'j' may be undefined [-Wsequence-point] 2 | int64_t n,d[6000]{0,1},m=666013,i=2,j;int main(){freopen("100m.in","r",stdin);for(std::cin>>n;i<=n;)for(j=i++;j;d[j--]=j*(d[j]+d[j-1])%m);for(freopen("100m.out","w",stdout);--i;j+=d[i]);std::cout<<j%m;} | ~^~ main.cpp:2:116: warning: operation on 'j' may be undefined [-Wsequence-point] main.cpp:2:116: warning: operation on 'j' may be undefined [-Wsequence-point] main.cpp:2:116: warning: operation on 'j' may be undefined [-Wsequence-point] main.cpp:2:116: warning: operation on 'j' may be undefined [-Wsequence-point] main.cpp:2:116: warning: operation on 'j' may be undefined [-Wsequence-point]