Submission #519263

#	Time	Username	Problem	Language	Result	Execution time	Memory
519263		N1NT3NDO	Index (COCI21_index)	C++14	60 / 110	2531 ms	128112 KiB

index

#include <bits/stdc++.h>
#define ll long long
#define pb push_back
//#include <ext/pb_ds/assoc_container.hpp>
//#include <ext/pb_ds/tree_policy.hpp>
#define sz(x) (int)x.size()
#define fi first
#define sd second
#define all(x) x.begin(), x.end()

using namespace std;
//using namespace __gnu_pbds;

//typedef tree<int, null_type, less<int>, rb_tree_tag, tree_order_statistics_node_update> ordered_set;
//#pragma GCC optimize("unroll-loops")
//#pragma GCC optimize("-O3")
//#pragma GCC optimize("avx2")

const int N = (int)2e5 + 5;
vector< int > t[4 * N], le[4 * N], ri[4 * N];
int a[N];
int n, q;

void build(int v, int tl, int tr)
{
    if (tl == tr)
    {
        t[v].pb(a[tl]);
        return;
    }

    int m = (tl + tr) >> 1;

    build(v * 2, tl, m);
    build(v * 2 + 1, m + 1, tr);

    int l = 0, r = 0;
    while(l < sz(t[v * 2]) || r < sz(t[v * 2 + 1]))
    {
        le[v].pb(l);
        ri[v].pb(r);
        if (l == sz(t[v * 2])) t[v].pb(t[v * 2 + 1][r]), r++;
        else if (r == sz(t[v * 2 + 1])) t[v].pb(t[v * 2][l]), l++;
        else if (t[v * 2][l] < t[v * 2 + 1][r]) t[v].pb(t[v * 2][l]), l++;
        else t[v].pb(t[v * 2 + 1][r]), r++;
    }

}

int get(int v, int tl, int tr, int l, int r, int x, int cur)
{
    if (tl > tr || tr < l || tl > r || cur >= sz(t[v])) return 0;

    if (v == 1)
      cur = lower_bound(all(t[v]), x) - t[v].begin();

    if (tl >= l && tr <= r)
      return sz(t[v]) - cur;

    int m = (tl + tr) >> 1;

    return get(v * 2, tl, m, l, r, x, le[v][cur]) + get(v * 2 + 1, m + 1, tr, l, r, x, ri[v][cur]);
}

int main()
{
    ios_base::sync_with_stdio(0); cin.tie(0);
    cin >> n >> q;
    for(int i = 1; i <= n; i++) cin >> a[i];
    build(1, 1, n);
    while(q--)
    {
        int l, r;
        cin >> l >> r;
        int lo = 1, hi = r - l + 1;
        while(lo < hi)
        {
            int mid = (lo + hi + 1) >> 1;

            if (get(1, 1, n, l, r, mid, 0) >= mid) lo = mid;
            else hi = mid - 1;
        }

        cout << lo << '\n';
    }
}

• Subtask 1: 20 / 20
• Subtask 2: 40 / 40
• Subtask 3: 0 / 50