Submission #333127

#	Time	Username	Problem	Language	Result	Execution time	Memory
333127		mohamedsobhi777	Bootfall (IZhO17_bootfall)	C++14	44 / 100	1099 ms	1184 KiB

bootfall

//stupid solution 1
#include <bits/stdc++.h>

#pragma GCC optimize("-Ofast")
//#pragma GCC optimize("trapv")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,sse4.2,popcnt,abm,mmx,avx2,tune=native")
#pragma GCC optimize("-ffast-math")
#pragma GCC optimize("-funroll-loops")

#define vi vector<int>
#define vii vector<pair<int, int>>
#define pii pair<int, int>
#define pll pair<ll, ll>
#define loop(_) for (int __ = 0; __ < (_); ++__)
#define forn(i, n) for (int i = 0; i < n; ++i)

using namespace std;
using ll = long long;
using ld = long double;

const int N = 500 + 7;
const int NN = N * N;
const ll mod = 1e9 + 7;
const ll inf = 2e18;

auto ra = [] {char *p = new char ; delete p ; return ll(p) ; };
mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count() * (ra() | 1));

int n;

bitset<NN> eval(vi v)
{
        bitset<NN> ret;
        ret[0] = 1;
        for (auto u : v)
                ret = (ret | (ret << u));
        return ret;
}

int ret[NN];

int main()
{
        ios_base::sync_with_stdio(0);
        cin.tie(0);
        //freopen("in.in", "r", stdin);
        cin >> n;
        vi a(n), ans;

        int sum = 0;
        for (auto &u : a)
                cin >> u;
        sum = accumulate(a.begin(), a.end(), 0);

        bitset<NN> bs = eval(a);
        if (sum & 1 || !bs[sum / 2])
                return cout << 0, 0;

        set<int> st;
        for (int i = 0; i < n; ++i)
        {
                int x = a[i];
                a[i] = 0;
                bitset<NN> bts = eval(a);
                int sm = sum - x;
                for (int j = 0; j <= sm; ++j)
                {
                        if (bts[j])
                        {
                                if (2 * j != sm)
                                        ret[abs(j - (sm - j))]++;
                        }
                }
                a[i] = x;
        }

        int sz = 0;
        for (int u = 1; u < NN; ++u)
        {
                if (ret[u] == 2 * n)
                        ans.push_back(u);
        }
        cout << (int)ans.size() << "\n";
        for (auto u : ans)
                cout << u << " ";
        return 0;
}

Compilation message (stderr)

bootfall.cpp: In function 'int main()':
bootfall.cpp:78:13: warning: unused variable 'sz' [-Wunused-variable]
   78 |         int sz = 0;
      |             ^~

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