Submission #878048

#	Time	Username	Problem	Language	Result	Execution time	Memory
878048		noiaint	Index (COCI21_index)	C++17	110 / 110	931 ms	14980 KiB

index

#include <bits/stdc++.h>

using namespace std;

#ifdef LOCAL
#include "debug.h"
#else
#define debug(...) 42
#endif

#define file ""

#define mp make_pair
#define fi first
#define se second
#define all(x) x.begin(), x.end()

#define bit(x) (1LL << (x))
#define getbit(x, i) (((x) >> (i)) & 1)
#define popcount __builtin_popcountll

mt19937_64 rd(chrono::steady_clock::now().time_since_epoch().count());
int rand(int l, int r) {
    return l + rd() % (r - l + 1);
}

const int N = 1e6 + 5;
const int mod = (int)1e9 + 7; // 998244353;
const int lg = 25; // lg + 1
const int oo = 1e9;
const long long ooo = 1e18;

template<class X, class Y> bool mini(X &a, Y b) {
    return a > b ? (a = b, true) : false;
}
template<class X, class Y> bool maxi(X &a, Y b) {
    return a < b ? (a = b, true) : false;
}
void add(int &a, int b) {
    a += b;
    if (a >= mod) a -= mod;
    if (a < 0) a += mod;
}

const int block = 750;

struct query {
    int l, r, id;
    query(int _l = 0, int _r = 0, int _id = 0) {
        l = _l;
        r = _r;
        id = _id;
    }
    bool operator < (const query &a) const {
        return l / block != a.l / block ? l / block < a.l / block : r < a.r;
    }
};

int n, q;
int a[N];
vector<query> queries;
int ans[N];
int bit[N];

void update(int u, int c) {
    for (; u <= n; u += u & (-u)) bit[u] += c;
}
int get(int u) {
    int res = 0;
    for (; u > 0; u -= u & (-u)) res += bit[u];
    return res;
}

void ins(int x) {
    update(x, 1);
}
void del(int x) {
    update(x, -1);
}

int getans(int x) {
    int l = 1, r = n;
    int res = 1;
    while (l <= r) {
        int mid = (l + r) / 2;
        if (mid + get(mid - 1) <= x) {
            res = mid;
            l = mid + 1;
        } else r = mid - 1;
    }
    return res;
}

void process() {
    cin >> n >> q;
    for (int i = 1; i <= n; ++i) cin >> a[i];
    for (int i = 1; i <= q; ++i) {
        int l, r;
        cin >> l >> r;
        queries.emplace_back(l, r, i);
    }
    sort(all(queries));
    int L = 1, R = 1;
    ins(a[1]);
    for (auto [l, r, id] : queries) {
        while (L < l) del(a[L++]);
        while (L > l) ins(a[--L]);
        while (R < r) ins(a[++R]);
        while (R > r) del(a[R--]);
        ans[id] = getans(r - l + 1);
    }   

    for (int i = 1; i <= q; ++i) cout << ans[i] << '\n';
}

int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);

    #ifdef LOCAL
    freopen("input.txt", "r", stdin);
    // freopen("output.txt", "w", stdout);
    #endif

    int tc = 1;
    // cin >> tc;
    
    while (tc--) {
        process();
    }

    return 0;
}

/*

*/  

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