Submission #1097711

#	Time	Username	Problem	Language	Result	Execution time	Memory
1097711		anhthi	Bootfall (IZhO17_bootfall)	C++14	100 / 100	373 ms	3388 KiB

bootfall

#include <bits/stdc++.h>
 
using namespace std;
 
#define fi first
#define se second
#define ll long long
#define mp(x, y) make_pair(x, y)
#define sz(v) ((int) (v).size())
#define all(v) (v).begin(), (v).end()
#define MASK(i) (1LL << (i))
#define BIT(x, y) (((x) >> (y)) & 1)
#define pb push_back
#define max_rng *max_element
#define min_rng *min_element
#define rep(i, n) for(int i = 1, _n = (n); i <= _n; ++i)
#define forn(i, a, b) for(int i = (a), _b = (b); i <= _b; ++i)
#define ford(i, a, b) for(int i = (a), _b = (b); i >= _b; --i)
 
template <class X, class Y>
    inline bool maximize(X &x, Y y) {
        return (x < y ? x = y, true : false);
    }
 
template <class X, class Y>
    inline bool minimize(X &x, Y y) {
        return (x > y ? x = y, true : false);
    }
 
template <class X>
    inline void compress(vector<X> &a) {
        sort(all(a));
        a.resize(unique(all(a)) - a.begin());
    }
 
int ctz(ll x) { return __builtin_ctzll(x); }
int lg(ll x) { return 63 - __builtin_clzll(x); }
int popcount(ll x) { return __builtin_popcount(x); }
 
mt19937_64 rng(chrono::high_resolution_clock::now().time_since_epoch().count());
ll rand(ll l, ll r) {
    return l + abs((ll) rng()) % (r - l + 1);
}
 
const ll oo = (ll) 1e17;
const int inf = (ll) 1e9 + 7, mod = (ll) 1e9 + 7;
 
const int N = 5e2 + 5, M = 250005, BASE = 307, LOG = 23;
 
void add(int &x, int y) { x += y; if (x >= mod) x -= mod; }
void sub(int &x, int y) { x -= y; if (x < 0) x += mod; }

int n;
int a[N];

int f[M];

int main(void) {
 
    ios_base::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);
    
    cin >> n;
    rep(i, n) cin >> a[i];

    int sum = accumulate(a + 1, a + 1 + n, 0);


    f[0] = 1;
    rep(i, n) ford(s, sum, a[i]) {
        add(f[s], f[s - a[i]]);
    }

    if (sum & 1 || !f[sum / 2]) return cout << 0, 0;
    
    vector<int> valid;
    rep(i, sum) valid.pb(i);

    rep(ban, n) {
        forn(s, a[ban], sum) sub(f[s], f[s - a[ban]]);

        vector<int> lst;
        for (int val : valid) {
            int res = sum - a[ban] + val;
            if (res & 1) continue;
            res >>= 1;
            if (f[res] > 0) {
                lst.pb(val);
            }
        }
        valid.swap(lst);

        ford(s, sum, a[ban]) add(f[s], f[s - a[ban]]);
    }
    cout << sz(valid) << '\n';
    for (int v : valid) cout << v << ' ';


    return 0;
}

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