Submission #948894

#	Time	Username	Problem	Language	Result	Execution time	Memory
948894		Nhoksocqt1	Permutation (APIO22_perm)	C++17	99 / 100	858 ms	704 KiB

perm

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

#define inf 0x3f3f3f3f
#define sz(x) int((x).size())
#define fi first
#define se second
typedef long long ll;
typedef pair<int, int> ii;

template<class X, class Y>
	inline bool maximize(X &x, const Y &y) {return (x < y ? x = y, 1 : 0);}
template<class X, class Y>
	inline bool minimize(X &x, const Y &y) {return (x > y ? x = y, 1 : 0);}

mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
int Random(int l, int r) {
    return uniform_int_distribution<int>(l, r)(rng);
}

const int MAXN = 6003;

ll fen[MAXN];
int nTree;

void modify(int i, ll v) {
    for (++i; i <= nTree; i += i & -i)
        fen[i] += v;
}

ll get(int i) {
    ll res(0);
    for (++i; i > 0; i -= i & -i)
        res += fen[i];

    return res;
}

ll calc(vector<int> &a) {
    ll res(1);
    nTree = sz(a) + 1;
    for (int i = 1; i <= nTree; ++i)
        fen[i] = 0;

    for (int it = 0; it < sz(a); ++it) {
        ll way = 1 + get(a[it]);
        modify(a[it], way);
        res += way;
    }

    return res;
}

vector<int> construct_permutation(ll k) {
    /*if(k <= 90) {
        vector<int> p;
        for (int i = k - 2; i >= 0; --i)
            p.push_back(i);

        return p;
    }*/

    vector<int> p;
    ll max_sum(0);
    int n(0);
    while(max_sum < k) {
        vector<int> new_p, idt;
        bool check(0);
        for (int it = 0; it <= sz(p); ++it)
            idt.push_back(it);

        shuffle(idt.begin(), idt.end(), rng);
        for (int x = 0; x < sz(idt); ++x) {
            int it(idt[x]);

            vector<int> tmp;
            for (int jt = 0; jt < it; ++jt)
                tmp.push_back(p[jt]);

            tmp.push_back(0);
            for (int jt = it; jt < sz(p); ++jt)
                tmp.push_back(p[jt]);

            vector<int> id;
            for (int t = 0; t <= n; ++t)
                id.push_back(t);

            shuffle(id.begin(), id.end(), rng);
            for (int z = 0; z < sz(id); ++z) {
                int t(id[z]);
                tmp[it] = t;
                for (int jt = 0; jt < sz(tmp); ++jt) {
                    if(it != jt && tmp[jt] >= t)
                        ++tmp[jt];
                }

                ll ans = calc(tmp);
                if(ans <= k && max_sum < ans) {
                    max_sum = ans;
                    new_p = tmp;
                    check = 1;
                }

                if(check && z > 10)
                    break;

                for (int jt = 0; jt < sz(tmp); ++jt) {
                    if(it != jt && tmp[jt] > t)
                        --tmp[jt];
                }
            }

            if(check && x > 10)
                break;
        }

        p = new_p;
        ++n;
    }

    return p;

    --k;
    for (int i = 64 - __builtin_clzll(k); i > 0; --i) {
        while(k >= (1LL << i) - 1) {
            vector<int> t;
            for (int j = 0; j < i; ++j)
                t.push_back(sz(p) + j);

            for (int it = 0; it < sz(p); ++it)
                t.push_back(p[it]);

            p = t;
            k -= (1LL << i) - 1;
        }
    }

    return p;
}

#ifdef Nhoksocqt1

int main(void) {
    ios_base::sync_with_stdio(0), cin.tie(0), cout.tie(0);

    #define TASK "perm"
    if(fopen(TASK".inp", "r")) {
        freopen(TASK".inp", "r", stdin);
        freopen(TASK".out", "w", stdout);
    }

    ll k;
    cin >> k;

    vector<int> a = construct_permutation(k);
    cout << "PERM SIZE: " << sz(a) << '\n';
    cout << "ANSWER PERM: ";
    for (int it = 0; it < sz(a); ++it)
        cout << a[it] << ' '; cout << '\n';

    cout << "NUM WAY: " << calc(a) << '\n';

    return 0;
}

#endif // Nhoksocqt1

• Subtask 1: 10 / 10
• Subtask 2: 89.000000001 / 90