Submission #878047

#	Time	Username	Problem	Language	Result	Execution time	Memory
878047		noiaint	Index (COCI21_index)	C++17	110 / 110	443 ms	90856 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;
}

int n, q;
int a[N];
pair<int, int> query[N];
vector<int> pos[N], v[N];
int l[N], r[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;
}
int get(int l, int r) {
    return get(r) - get(l - 1);
}

void process() {
    cin >> n >> q;
    for (int i = 1; i <= n; ++i) {
        cin >> a[i];
        pos[a[i]].push_back(i);
    }
    for (int i = 1; i <= q; ++i) {
        cin >> query[i].fi >> query[i].se;
        l[i] = 1, r[i] = n + 1;
    }
    while (true) {
        bool ok = true;
        for (int i = 1; i <= q; ++i) {
            if (l[i] <= r[i]) v[(l[i] + r[i]) / 2].push_back(i);
            if (r[i] - l[i] > 1) ok = false;
        }
        if (ok) break;
        
        memset(bit, 0, sizeof bit);
        for (int i = n; i >= 1; --i) {
            for (int j : pos[i]) update(j, 1);
            for (int id : v[i]) {
                if (get(query[id].fi, query[id].se) >= i) l[id] = i;
                else r[id] = i;
            }
            v[i].clear();
        }
    }

    for (int i = 1; i <= q; ++i) cout << l[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