Submission #333006

#	Time	Username	Problem	Language	Result	Execution time	Memory
333006		Dymo	Bootfall (IZhO17_bootfall)	C++14	100 / 100	219 ms	2924 KiB

bootfall

#include<bits/stdc++.h>
using namespace std;


#define pb    push_back
#define eb   emplace_back
#define ll  int
#define pll pair<ll,ll>
#define ff first
#define ss second
#define endl "\n"
const ll maxn=500*500+10;
const ll mod =1e9+7 ;
const ll base=1e18;
const ll block=1000;
/// con 0 ngay nua
/// zesitahn
ll a[maxn];
bitset<maxn> st1;
ll t=0;
void dosth(ll l,ll r,bitset<maxn> st)
{
    if (l==r)
    {
        bitset<maxn>chk;
         for (int i=1;i<maxn;i++)
         {
           ll cl=t-a[l]-i;
           if (cl<0) break;
           if (cl%2==0)
           {
               cl/=2;

               if (st[cl]==1) chk[i]=1;
           }
         }
         st1&=chk;
         return ;
    }
    ll mid=(l+r)/2;
    auto nxt=st;
    for (int i=mid+1;i<=r;i++)
    {
        nxt|=(nxt<<a[i]);
    }
    dosth(l,mid,nxt);
    nxt=st;
    for (int i=l;i<=mid;i++)
    {
        nxt|=(nxt<<a[i]);
    }
    dosth(mid+1, r, nxt);
}
bool chk(ll n)
{
   if (t%2==1) return false;
   bitset<maxn> st;
   st[0]=1;
   for (int i=1;i<=n;i++)
   {
       st|=(st<<a[i]);
   }
 //  cout <<t/2<<endl;
   return st[t/2];
}
int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
    if (fopen("queue.inp", "r"))
    {
        freopen("queue.inp", "r", stdin);
        freopen("queue.out", "w", stdout);
    }
    ll n;
     cin>> n;
     for (int i=1;i<=n;i++)
     {
         cin>>a[i];
         t+=a[i];
     }
     if (!chk(n))
     {
         cout <<0;
         return 0;
     }
     bitset<maxn> st;
     st[0]=1;
     for (int i=1;i<maxn;i++)
     {
         st1[i]=1;
     }
     dosth(1,n,st);
     vector<ll> ans;
     for (int i=1;i<maxn;i++)
     {
         if (st1[i]) ans.pb(i);
     }
     cout <<ans.size()<<endl;
     for (auto to:ans)
     {
         cout <<to<<" ";
     }

}

Compilation message (stderr)

bootfall.cpp:14:15: warning: overflow in conversion from 'double' to 'int' changes value from '1.0e+18' to '2147483647' [-Woverflow]
   14 | const ll base=1e18;
      |               ^~~~
bootfall.cpp: In function 'int main()':
bootfall.cpp:73:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
   73 |         freopen("queue.inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
bootfall.cpp:74:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
   74 |         freopen("queue.out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 6 / 6
• Subtask 2: 7 / 7
• Subtask 3: 15 / 15
• Subtask 4: 16 / 16
• Subtask 5: 21 / 21
• Subtask 6: 35 / 35