Submission #1128072

#	Time	Username	Problem	Language	Result	Execution time	Memory
1128072		Vietnow	Bootfall (IZhO17_bootfall)	C++20	28 / 100	1099 ms	240540 KiB

bootfall

#include <bits/stdc++.h>
#define yes cout<<"YES\n"
#define no cout<<"NO\n"
#define int long long
#define ff first
#define ss second
#define pb push_back
#define y1 zildjian
#define left radio
#define right head
 
using namespace std;
 
const int N = 501;
const int INF = 1e18;
const int mod = 1e9+7;
const int mod1 = 998244353;
mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());

int n;
int a[N];
map<pair<int,int>,bool> m;

void solve(){
    cin>>n;
    int sum = 0;
    for(int i = 1;i<=n;i++){
        cin>>a[i];
        sum+=a[i];
    }
    if(sum%2){
        cout<<0;
        return;
    }
    int dp[sum+1];
    memset(dp,0,sizeof(dp));
    for(int i = 2;i<=n;i++){
        if(a[i]%2 != a[i-1]%2){
            cout<<'0';
            return;
        }
    }
    dp[0] = 1;
    for(int i = 1;i<=n;i++){
        for(int w = sum;w>=a[i];w--){
            dp[w] += dp[w-a[i]];
        }
    }
    if(!dp[sum/2]){
        cout<<0<<'\n';
        return;
    }
    for(int i = 1;i<=n;i++){
        vector<int> buf;
        for(int w = 0;w<=sum;w++){
            buf.pb(dp[w]);
        }
        for(int w = 0;w+a[i]<=sum;w++){
            if(dp[w] && dp[w+a[i]]){
                dp[w+a[i]] -= dp[w];
            }
        }
        for(int w = 0;w<=sum;w++){
            if(dp[w]) m[{w,i}] = 1;
            dp[w] = buf[w];
        }
    }
    int x = 1;
    if(a[1]%2 == 0) x++;
    vector<int> ans;
    for(;x<=sum;x+=2){
        bool ok = 1;
        // cout<<x<<'\n';
        for(int i = 1;i<=n;i++){
            // w = (sum-a[i]+x)/2
            // w-x = (sum-a[i]+x)/2-x;
            if((sum-a[i]+x)%2 || !m[{(sum-a[i]+x)/2-x,i}]){
                ok = 0;
                break;
            }
        }
        if(ok){
            ans.pb(x);
        }
    }
    // cout<<'\n';
    cout<<ans.size()<<'\n';
    for(auto x:ans) cout<<x<<' ';
    cout<<'\n';
}

signed main(){
    // freopen("bootfall.in","r",stdin); 
    // freopen("bootfall.out","w",stdout);
    ios_base::sync_with_stdio(0);
    cin.tie(nullptr);
    // cout.tie(nullptr);
    int t = 1;
    // cin>>t;
    for(int i = 1;i<=t;i++){
        // cout<<"Case "<<i<<": ";
        solve();
    }
}

• Subtask 1: 6 / 6
• Subtask 2: 7 / 7
• Subtask 3: 15 / 15
• Subtask 4: 0 / 16
• Subtask 5: 0 / 21
• Subtask 6: 0 / 35