Submission #1126569

#	Time	Username	Problem	Language	Result	Execution time	Memory
1126569		Gray	Bootfall (IZhO17_bootfall)	C++20	65 / 100	1014 ms	38864 KiB

bootfall

#include <algorithm>
#include <bits/stdc++.h>
#include <iomanip>
using namespace std;
#define ll long long
#define ull unsigned long long
#define ld long double
#define ff first
#define ss second
#define ln "\n"
#define mp make_pair
const ll MOD = 1e9+7;
const ll INF = 2e18;

struct SparseTable{
    vector<vector<ll>> t; ll n;
    vector<ll> log;
    ll func(ll a, ll b){
        return min(a, b);
    }
    void init(ll N, vector<ll> &a){
        n=N; log.resize(n+1);
        for (ll i=2; i<=n; i++) log[i]=log[i/2]+1;
        t.resize(log[N]+1, vector<ll>(n));
        t[0]=a;
        for (ll i=1; i<=log[n]; i++){
            for (ll j=0; j<=n-(1<<i); j++){
                t[i][j]=func(t[i-1][j], t[i-1][j+(1<<(i-1))]);
            }
        }
    }
    ll query(ll l, ll r){
        ll lg = log[r-l+1];
        return func(t[lg][l], t[lg][r-(1<<lg)+1]);
    }
};


void solve(){
    ll n; cin >> n;
    vector<ll> a(n);
    bitset<500*600> dp;
    ll sm=0;
    for (ll i=0; i<n; i++){
        cin >> a[i]; sm+=a[i];
        dp = (dp<<a[i])|dp;
        dp.set(a[i]);
    }
    if (!(dp[sm/2] and sm%2==0)){
        cout << 0 << ln; return;
    }
    bitset<500*600> pos;
    for (ll i=1; i<=250000; i++) pos.set(i);
    vector<bitset<500*600>> pref(n), suff(n); pref[0].set(0); suff[n-1]=pref[0];
    for (ll i=0; i<n; i++){
        if (i) pref[i]|=pref[i-1];
        pref[i] = (pref[i]<<a[i])|pref[i];
        pref[i].set(a[i]);
    }
    for (ll i=n-1; i>=0; i--){
        if (i!=n-1) suff[i]|=suff[i+1];
        suff[i] = (suff[i]<<a[i])|suff[i];
        suff[i].set(a[i]);
    }
    for (ll i=0; i<n; i++){
        dp.reset(); dp.set(0);
        ll sum=0;
        for (ll j=0; j<n; j++){
            if (i==j) continue;
            sum+=a[j];
        }
        if (i<n/2){
            dp = suff[i+1];
            for (ll j=0; j<i; j++) {
                dp=(dp<<a[j])|dp;
                dp.set(a[j]);
            }
        }else{
            if (i-1>=0) dp = pref[i-1];
            for (ll j=n-1; j>i; j--){
                dp = (dp<<a[j])|dp;
                dp.set(a[j]);
            }
        }
        // cout << i << ": ";
        for (ll j=1; j<=250000; j++){
            if ((sum-j)%2 or sum<j or !dp[(sum-j)/2]) {
                pos.reset(j);
                // if (j==600) cout << sum-j << " - " << (!dp[(sum-j)/2]) << ln;
            }
        }
        // cout << ln;
    }
    vector<ll> res;
    for (ll i=1; i<=250000; i++){
        if (pos[i]) res.push_back(i);
    }
    cout << res.size() << ln;
    for (auto ch:res) cout << ch << " ";
    cout << ln;
}

int main(){
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    auto start = chrono::high_resolution_clock::now();
    ll t=1;
    // cin >> t;
    while (t--) solve();
    #ifdef LOCAL
    auto duration = chrono::duration_cast<chrono::microseconds>(chrono::high_resolution_clock::now() - start);
    cout << setprecision(0) << fixed << "time: " << (double)duration.count()/1000.0 << " milliseconds" << endl;
    #endif
}

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