제출 #1275221

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1275221		CrabCNH	Index (COCI21_index)	C++20	110 / 110	355 ms	54752 KiB

index

#include <bits/stdc++.h>

#define task   "htgdtctn"

#define int    long long
#define pii    pair <int, int>
#define fi     first
#define se     second
#define szf    sizeof
#define sz(s)  (int)((s).size())
#define all(v) (v).begin(), (v).end()

using namespace std;

template <class T> void minimize (T &t, T f) {if (t > f) t = f;}
template <class T> void maximize (T &t, T f) {if (t < f) t = f;}

const int maxN = 2e5 + 5;
const int inf = 1e18 + 7;
const int mod = 1e9 + 7;

// mt19937_64 rd (chrono :: steady_clock :: now ().time_since_epoch ().count ());
// int Rand (int l, int r) {return uniform_int_distribution <int> (l, r) (rd);}

int n, q;
pii qs[maxN];
int lq[maxN], rq[maxN], res[maxN];
vector <int> val[maxN];
vector <int> event[maxN];

struct Fenwick {
    int n;
    vector <int> bit;
    
    inline void init (int _n) {
        n = _n;
        bit.resize (n + 2, 0);
    }
    
    inline void flush () {
        fill (all (bit), 0);
    }
    
    inline void upd (int id, int val) {
        for (; id <= n; id += id & (-id)) {
            bit[id] += val;
        }
    }
    
    inline int get (int id) {
        int res = 0;
        for (; id; id -= id & (-id)) {
            res += bit[id];
        }
        return res;
    }
};

Fenwick T;

inline void Solve () {
    cin >> n >> q;
    for (int i = 1; i <= n; i ++) {
        int a;
        cin >> a;
        val[a].push_back (i);
    }
    for (int i = 1; i <= q; i ++) {
        int x, y;
        cin >> x >> y;
        qs[i] = {x, y};
        lq[i] = 1;
        rq[i] = n;
    }
    T.init (n);
    while (true) {
        bool ck = 0;
        T.flush ();
        for (int i = 1; i <= q; i ++) {
            //cout << lq[i] << ' ' << rq[i] << '\n';
            if (lq[i] > rq[i]) {
                continue;
            }
            ck = 1;
            int mid = (lq[i] + rq[i]) >> 1;
            event[mid].push_back (i);
        }
        if (!ck) {
            break;
        }
        for (int mid = n; mid >= 0; mid --) {
            for (auto it : val[mid]) {
                T.upd (it, 1);
            }
            for (auto it : event[mid]) {
                //cout << qs[it].se << ' ' << qs[it].fi - 1 << '\n';
                if (T.get (qs[it].se) - T.get (max (qs[it].fi - 1, 0LL)) >= mid) {
                    res[it] = mid;
                    lq[it] = mid + 1;
                } 
                else {
                    rq[it] = mid - 1;
                }
            }
            event[mid].clear ();
        }
    }
    for (int i = 1; i <= q; i ++) {
        cout << res[i] << '\n';
    }
    return;
}

signed main () {
    cin.tie (nullptr) -> sync_with_stdio (false);
    if (fopen (task".inp", "r")) {
        freopen (task".inp", "r", stdin);
        freopen (task".out", "w", stdout);
    }
    int t = 1;
    //cin >> t;
    while (t --) {
        Solve ();
    } 
    return 0;
}
// wake me up when September ends

컴파일 시 표준 에러 (stderr) 메시지

index.cpp: In function 'int main()':
index.cpp:117:17: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  117 |         freopen (task".inp", "r", stdin);
      |         ~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
index.cpp:118:17: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  118 |         freopen (task".out", "w", stdout);
      |         ~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

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