Submission #884472

#	Time	Username	Problem	Language	Result	Execution time	Memory
884472		tsumondai	Bootfall (IZhO17_bootfall)	C++14	100 / 100	229 ms	3820 KiB

bootfall

// DNC DP

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

#define fi first
#define se second
#define pb push_back
#define mp make_pair
#define foru(i, l, r) for(int i = l; i <= r; i++)
#define ford(i, r, l) for(int i = r; i >= l; i--)
#define __TIME  (1.0 * clock() / CLOCKS_PER_SEC)

typedef pair<int, int> ii;
typedef pair<ii, int> iii;
typedef pair<ii, ii> iiii;

const int N = 1e6 + 5;

const int oo = 1e9, mod = 1e9 + 7;

int n, m, k, a[N];
int dp[500 * 500 + 5], cnt[500 * 500 + 5];
vector<int> res;

void process() {
    cin >> n;
    int sum = 0;
    foru(i, 1, n) {
        cin >> a[i];
        sum += a[i];
    }

    dp[0] = 1;

    foru(i, 1, n) {
        ford(j, sum - a[i], 0) {
            dp[j + a[i]] += dp[j];
        }
    }

    if ((sum & 1) || !dp[(sum >> 1)]) {
        cout << 0 << '\n';
        return;
    }

    foru(i, 1, n) {
        int x = sum - a[i];
        foru(j, 0, sum - a[i]) {
            dp[j + a[i]] -= dp[j];
        }
        foru(j, (x + 1) >> 1, x) {
            cnt[(j << 1) - x] += !!dp[j];
        }
        ford(j, sum - a[i], 0) {
            dp[j + a[i]] += dp[j];
        }
    }
    foru(i, 0, sum) if (cnt[i] == n) res.pb(i);

    cout << res.size() << '\n';
    for (auto x : res) cout << x << ' ';

    return;
}

signed main() {
    cin.tie(0)->sync_with_stdio(false);
    //freopen(".inp", "r", stdin);
    //freopen(".out", "w", stdout);
    process();
    cerr << "Time elapsed: " << __TIME << " s.\n";
    return 0;
}

// dont stop

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