Submission #520621

#	Time	Username	Problem	Language	Result	Execution time	Memory
520621		Vimmer	Cigle (COI21_cigle)	C++14	48 / 100	1096 ms	218260 KiB

cigle

#include <bits/stdc++.h>
#define in(x) freopen(x, "r", stdin)
#define out(x) freopen(x, "w", stdout)

#pragma GCC optimize("Ofast")
#pragma GCC optimize("unroll-loops")
#pragma GCC optimize("-O3")

#define F first
#define S second
#define PB push_back
#define M ll(1e9 + 7)
#define sz(x) (ll)x.size()
#define N 1000500
#define pri(x) cout << x << endl
#define endl '\n'
#define all(x) (x).begin(), (x).end()
#define _ << " " <<

using namespace std;
//typedef tree <ll, null_type, less_equal <ll> , rb_tree_tag, tree_order_statistics_node_update> ordered_set;
//using namespace __gnu_pbds;
typedef long long ll;
typedef long double ld;
typedef short int si;
typedef unsigned long long ull;

si f[5001][5001][2];

vector <int> was[5001];

int pr[5001];

si now[5001][5001][2];

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

    memset(f, -1, sizeof f);

    int n;

    cin >> n;

    int a[n];

    si ans = 0;

    for (int i = 0; i < n; i++)
        cin >> a[i];

    for (int i = 0; i < n; i++)
    {
        pr[i] = a[i];

        if (i)
            pr[i] += pr[i - 1];
    }

    for (int l = 0; l < n; l++)
        {
            int sum = 0;

            for (int r = l; r < n; r++)
            {
                sum += a[r];

                int L = r + 1, R = n - 1;

                while (L < R)
                {
                    int md = (L + R) >> 1;

                    if (pr[md] - pr[r] >= sum)
                        R = md;
                            else L = md + 1;
                }

                if (pr[L] - pr[r] == sum)
                    {
                        was[r].PB(L);
                    }
            }
        }

    for (int i = 0; i < n; i++)
        sort(all(was[i]));

    memset(now, -1, sizeof now);

    for (int i = 0; i < n; i++)
        f[0][i][0] = 0;

    for (int r = 0; r < n; r++)
        for (int l = 0; l <= r; l++)
                for (int t = 0; t < 2; t++)
                {
                    if (r)
                        now[l][r][t] = max(now[l][r][t], now[l][r - 1][t]);

                    f[l][r][t] = max(f[l][r][t], now[l][r][t]);

                    if (f[l][r][t] != -1)
                        {
                            si kl = f[l][r][t];

                            int sm = pr[r], cur = 0;

                            if (l)
                                sm -= pr[l - 1];
                            for (auto nw : was[r])
                            {
                                cur = pr[nw] - pr[r];

                                if (cur >= sm)
                                {
                                    now[r + 1][nw][t ^ 1] = max(now[r + 1][nw][t ^ 1], si(kl));

                                    break;
                                }
                                else
                                {
                                    if (nw != n - 1)
                                        {
                                            kl++;

                                            now[r + 1][nw + 1][t ^ 1] = max(now[r + 1][nw + 1][t ^ 1], si(kl));
                                        }

                                    ans = max(ans, kl);
                                }
                            }
                        }
                }

    pri(ans);
}

• Subtask 1: 9 / 9
• Subtask 2: 11 / 11
• Subtask 3: 13 / 13
• Subtask 4: 15 / 15
• Subtask 5: 0 / 52