Submission #519279

#	Time	Username	Problem	Language	Result	Execution time	Memory
519279		N1NT3NDO	Index (COCI21_index)	C++14	110 / 110	2459 ms	118048 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("Ofast")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")

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

    t[v].resize(sz(t[v << 1]) + sz(t[v * 2 + 1]));
    le[v].resize(sz(t[v]));
    ri[v].resize(sz(t[v]));

    merge(all(t[v << 1]), all(t[v * 2 + 1]), t[v].begin());

    int l = 0, r = 0;
    for(int i = 0; i < sz(t[v]); i++)
    {
        int u = t[v][i];
        while(l < sz(t[v << 1]) && t[v << 1][l] < u) l++;
        while(r < sz(t[v * 2 + 1]) && t[v * 2 + 1][r] < u) r++;
        le[v][i] = l;
        ri[v][i] = 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 (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::sync_with_stdio(0); cin.tie(0); cout.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, lower_bound(all(t[1]), mid) - t[1].begin()) >= mid) lo = mid;
            else hi = mid - 1;
        }

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

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