Submission #512174

#	Time	Username	Problem	Language	Result	Execution time	Memory
512174		blue	Teams (CEOI11_tea)	C++17	100 / 100	2279 ms	113192 KiB

tea

#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;

using vi = vector<int>;
using pii = pair<int, int>;
using vvi = vector<vi>;
#define sz(x) int(x.size())

const int INF = 100'000'000;

const int Z = (1<<20);
vector<int> segtree;

void set(int i, int v)
{
    i += Z;
    segtree[i] = v;
    for(i >>= 1; i >= 1; i >>= 1) segtree[i] = max(segtree[i<<1], segtree[(i<<1) | 1]);
}


vector<pii> segtree2;
void set2(int i, int v)
{
    // cerr << "\n\n" << "set2 " << i << ' ' << v << '\n';
    i += Z;
    segtree2[i].first = v;
    for(i >>= 1; i >= 1; i >>= 1) segtree2[i] = max(segtree2[i<<1], segtree2[(i<<1) | 1]);
    // cerr << "root = " << segtree2[1]
}




int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);

    int n;
    cin >> n;

    pii a[1+n];
    for(int i = 1; i <= n; i++)
    {
        cin >> a[i].first;
        a[i].second = i;
    }
    sort(a+1, a+n+1);

    int t;

    vi dp(1+n);
    vi dpmx(1+n);

    dp[0] = dpmx[0] = 0;

    for(int i = 1; i <= n; i++)
    {
        t = -INF;
        if(a[i].first > i)
        {
            ;
        }
        else
        {
            if(i - a[i].first >= 0)
                t = dpmx[i - a[i].first];
        }

        dp[i] = max(-INF, t + 1);
        dpmx[i] = max(dp[i], dpmx[i-1]);

        // cerr << i << " : " << t << '\n';
    }

    int team_count = dp[n];

    // int Z = (1<<20);

    int z = 0;
    for(int i = 1; i <= n; i++) z = max(z, a[i].first);


    int lo = 1, hi = n;
    while(lo != hi)
    {
        int mxs = (lo+hi)/2;

        segtree = vector<int>(Z<<1, -INF);

        int l = 0;
        int r = -1;

        vi new_dp(1+n, -INF);
        new_dp[0] = 0;

        // cerr << "n = " << n << '\n';

        for(int i = 1; i <= n; i++)
        {
            int nl = max(0, i-mxs);
            int nr = max(-1, i - a[i].first);



            if(nl > nr) continue;


            if(nr - nl < 30)
            {
                for(int g = nl; g <= nr; g++)
                    new_dp[i] = max(new_dp[i], new_dp[g]+1);
                continue;
            }

            while(r < nr)
            {
                r++;
                set(r, new_dp[r]);
            }

            while(l > nl)
            {
                l--;
                set(l, new_dp[l]);
            }

            while(r > nr)
            {
                set(r, -INF);
                r--;
            }

            while(l < nl)
            {
                set(l, -INF);
                l++;
            }

            new_dp[i] = max(-INF, segtree[1]+1);
        }

        if(new_dp[n] == team_count)
            hi = mxs;
        else
            lo = mxs+1;
    }

    // cerr << team_count << ' ' << lo << '\n';







        int mxs = lo;

        // cerr << "\n\n\n\n\n";
        // cerr << lo << ' ' << hi << " : " << mxs << '\n';

        segtree2 = vector<pii>(Z<<1, {-INF, -1});
        for(int i = 0; i <= n; i++) segtree2[Z+i].second = i;

        int l = 0;
        int r = -1;

        vi new_dp(1+n, -INF);
        new_dp[0] = 0;

        vi prv(1+n, -1);

        // cerr << "n = " << n << '\n';

        for(int i = 1; i <= n; i++)
        {
            int nl = max(0, i-mxs);
            int nr = max(-1, i - a[i].first);

            if(nr - nl < 20)
            {
                for(int i2 = nl; i2 <= nr; i2++)
                {
                    if(new_dp[i2]+1 >= new_dp[i])
                    {
                        new_dp[i] = new_dp[i2] + 1;
                        prv[i] = i2;
                    }
                }
                continue;
            }
            // if(i-mxs > i - a[i]) con
            // cerr << "i = " << i << " : " << "nl nr = " << nl << ' ' << nr << '\n';
            if(nl > nr) continue;

            // cerr << "journey " << l << ' ' << r << " -> " << nl << ' ' << nr << '\n';

            while(r < nr)
            {
                r++;
                set2(r, new_dp[r]);
            }

            while(l > nl)
            {
                l--;
                set2(l, new_dp[l]);
            }

            while(r > nr)
            {
                set2(r, -INF);
                r--;
            }

            while(l < nl)
            {
                set2(l, -INF);
                l++;
            }
            // cerr << l << ' ' << r << '\n';
            // cerr << "st = " << segtree2[1].first << ' ' << segtree2[1].second << '\n';

            new_dp[i] = max(-INF, segtree2[1].first+1);
            prv[i] = segtree2[1].second;

            // cerr << i << " : " << new_dp[i] << ' ' << prv[i] << '\n';
        }

        vvi teams;
           int I = n;
           while(I != 0)
           {
               teams.push_back(vi(0));
               // cerr << I << ' ' << prv[I] << '\n';
               for(int q = I; q > prv[I]; q--)
                   teams.back().push_back(a[q].second);
               I = prv[I];
           }

           cout << team_count << '\n';
           for(int f = 0; f < team_count; f++)
           {
               cout << sz(teams[f]) << ' ';
               for(int w: teams[f]) cout << w << ' ';
               cout << '\n';
           }
           return 0;
}

• Subtask 1: 10 / 10
• Subtask 2: 10 / 10
• Subtask 3: 10 / 10
• Subtask 4: 10 / 10
• Subtask 5: 10 / 10
• Subtask 6: 10 / 10
• Subtask 7: 10 / 10
• Subtask 8: 10 / 10
• Subtask 9: 10 / 10
• Subtask 10: 10 / 10