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Submission #683103

# Submission time Handle Problem Language Result Execution time Memory
683103 2023-01-17T16:58:39 Z nutella Abracadabra (CEOI22_abracadabra) C++17
100 / 100
 621 ms 47360 KB 
#include <bits/stdc++.h>

using namespace std;

struct Fenwick {
    vector<int> t;
    int n, S = 0;

    Fenwick() = default;

    Fenwick(int n) : n(n), t(n + 1) {}

    void modify(int i, int v) {
        S += v;
        for (int x = i + 1; x <= n; x += x & -x) {
            t[x] += v;
        }
    }

    int sum(int i) {
        int ans = 0;
        for (int x = i + 1; x > 0; x -= x & -x) {
            ans += t[x];
        }
        return ans;
    }

    int lower_bound(int k) {
        int x = 0;
        for (int i = 1 << __lg(n); i > 0; i >>= 1) {
            if (x + i <= n && t[x + i] < k) {
                x += i;
                k -= t[x];
            }
        }
        return x;
    }
};

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

    int n, q;
    cin >> n >> q;

    vector<int> a(n);

    for (int &x: a) {
        cin >> x;
        x -= 1;
    }

    vector<int> ans(q, -1);

    vector<vector<array<int, 2>>> queries(n + 1);

    for (int i = 0; i < q; ++i) {
        int t, p;
        cin >> t >> p;

        p -= 1;

        if (t == 0) {
            ans[i] = a[p];
            continue;
        }

        queries[min(t, n)].push_back({i, p});
    }

    const int logn = __lg(n) + 1;

    auto comp = [&](int i, int j) {
        return a[i] > a[j] ? i : j;
    };

    vector<vector<int>> mx(logn);

    mx[0].resize(n);
    iota(mx[0].begin(), mx[0].end(), 0);

    for (int l = 1; l < logn; ++l) {
        mx[l].resize(n - (1 << l) + 1);

        for (int i = 0; i + (1 << l) <= n; ++i) {
            mx[l][i] = comp(mx[l - 1][i], mx[l - 1][i + (1 << l - 1)]);
        }
    }

    auto rangeMax = [&](int l, int r) {
        int lg = __lg(r - l);

        return comp(mx[lg][l], mx[lg][r - (1 << lg)]);
    };

    Fenwick fn(n);

    vector<pair<int, int>> segment(n, {-1, -1});

    int pref_mx = -1;
    for (int i = 0; i < n / 2; ++i) {
        if (pref_mx < a[i]) {
            if (pref_mx != -1) {
                segment[pref_mx].second = i;
            }
            
            pref_mx = a[i];
            segment[pref_mx].first = i;
        }
    }
    segment[pref_mx].second = n / 2;

    pref_mx = -1;
    for (int i = n / 2; i < n; ++i) {
        if (pref_mx < a[i]) {
            if (pref_mx != -1) {
                segment[pref_mx].second = i;
            }
            
            pref_mx = a[i];
            segment[pref_mx].first = i;
        }
    }
    segment[pref_mx].second = n;

    for (int x = 0; x < n; ++x) {
        if (segment[x].first != -1) {
            fn.modify(x, segment[x].second - segment[x].first);
        }
    }

    auto find_next = [&](int l, int r) {
        int mx = rangeMax(l, r);
        if (l == mx) {
            return -1;
        }

        int lo = l, hi = r;
        while (lo + 1 < hi) {
            int mid = (lo + hi) >> 1;

            if (rangeMax(l, mid + 1) == l) {
                lo = mid;
            } else {
                hi = mid;
            }
        }

        return hi;
    };

    auto getValue = [&](int p) {
        p += 1;

        int x = fn.lower_bound(p);
        int sum_l = fn.sum(x - 1);

        return a[segment[x].first + (p - sum_l) - 1];
    };
    
    for (int t = 1; t <= n; ++t) {
        for (auto [i, p]: queries[t]) {
            ans[i] = getValue(p);
        }

        int x = fn.lower_bound(n / 2);
        int sum = fn.sum(x);

        if (sum == n / 2) {
            continue;
        }

        int sum_l = sum - (segment[x].second - segment[x].first);
        int cut = segment[x].first + (n / 2 - sum_l);

        fn.modify(x, cut - segment[x].second);

        int l = cut, r = segment[x].second;

        segment[x].second = cut;

        while (l < r) {
            int mid = find_next(l, r);

            if (mid == -1) {
                segment[a[l]].first = l, segment[a[l]].second = r;
            } else {
                segment[a[l]].first = l, segment[a[l]].second = mid;
            }

            fn.modify(a[l], segment[a[l]].second - segment[a[l]].first);

            l = segment[a[l]].second;
        }
    }

    for (int i = 0; i < q; ++i) {
        cout << ans[i] + 1 << '\n';
    }

    return 0;
}

Compilation message

Main.cpp: In constructor 'Fenwick::Fenwick(int)':
Main.cpp:7:9: warning: 'Fenwick::n' will be initialized after [-Wreorder]
    7 |     int n, S = 0;
      |         ^
Main.cpp:6:17: warning:   'std::vector<int> Fenwick::t' [-Wreorder]
    6 |     vector<int> t;
      |                 ^
Main.cpp:11:5: warning:   when initialized here [-Wreorder]
   11 |     Fenwick(int n) : n(n), t(n + 1) {}
      |     ^~~~~~~
Main.cpp: In function 'int main()':
Main.cpp:87:65: warning: suggest parentheses around '-' inside '<<' [-Wparentheses]
   87 |             mx[l][i] = comp(mx[l - 1][i], mx[l - 1][i + (1 << l - 1)]);
      |                                                               ~~^~~

Subtask #1
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 271 ms 18904 KB Output is correct
2 Correct 309 ms 17580 KB Output is correct
3 Correct 265 ms 17096 KB Output is correct
4 Correct 212 ms 16008 KB Output is correct
5 Correct 339 ms 19296 KB Output is correct
6 Correct 273 ms 19980 KB Output is correct
7 Correct 242 ms 20440 KB Output is correct
8 Correct 227 ms 18280 KB Output is correct
9 Correct 223 ms 17140 KB Output is correct
10 Correct 290 ms 17008 KB Output is correct
11 Correct 216 ms 17380 KB Output is correct
12 Correct 198 ms 14400 KB Output is correct
13 Correct 220 ms 16176 KB Output is correct
14 Correct 231 ms 18752 KB Output is correct
15 Correct 232 ms 16312 KB Output is correct
16 Correct 1 ms 340 KB Output is correct
17 Correct 182 ms 8552 KB Output is correct
18 Correct 191 ms 12216 KB Output is correct
19 Correct 1 ms 212 KB Output is correct
20 Correct 1 ms 212 KB Output is correct

Subtask #2
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 345 ms 40128 KB Output is correct
2 Correct 335 ms 40128 KB Output is correct
3 Correct 274 ms 35600 KB Output is correct
4 Correct 273 ms 35696 KB Output is correct
5 Correct 256 ms 36440 KB Output is correct
6 Correct 298 ms 35028 KB Output is correct
7 Correct 329 ms 39908 KB Output is correct
8 Correct 304 ms 38396 KB Output is correct
9 Correct 302 ms 36260 KB Output is correct
10 Correct 299 ms 38192 KB Output is correct
11 Correct 237 ms 35960 KB Output is correct
12 Correct 280 ms 35056 KB Output is correct
13 Correct 297 ms 38380 KB Output is correct
14 Correct 252 ms 36156 KB Output is correct
15 Correct 345 ms 39216 KB Output is correct
16 Correct 41 ms 21512 KB Output is correct
17 Correct 268 ms 31108 KB Output is correct
18 Correct 237 ms 34984 KB Output is correct
19 Correct 85 ms 23360 KB Output is correct
20 Correct 113 ms 24084 KB Output is correct

Subtask #3
25.0 / 25.0

# Verdict Execution time Memory Grader output
1 Correct 83 ms 13928 KB Output is correct
2 Correct 93 ms 13440 KB Output is correct
3 Correct 73 ms 13216 KB Output is correct
4 Correct 49 ms 12956 KB Output is correct
5 Correct 55 ms 13580 KB Output is correct
6 Correct 52 ms 12816 KB Output is correct
7 Correct 65 ms 13380 KB Output is correct
8 Correct 53 ms 12712 KB Output is correct
9 Correct 57 ms 13368 KB Output is correct
10 Correct 51 ms 12576 KB Output is correct
11 Correct 52 ms 13152 KB Output is correct
12 Correct 47 ms 12624 KB Output is correct
13 Correct 44 ms 12560 KB Output is correct
14 Correct 45 ms 13060 KB Output is correct
15 Correct 42 ms 12796 KB Output is correct
16 Correct 17 ms 10460 KB Output is correct
17 Correct 40 ms 11416 KB Output is correct
18 Correct 37 ms 11884 KB Output is correct
19 Correct 1 ms 212 KB Output is correct
20 Correct 1 ms 212 KB Output is correct

Subtask #4
25.0 / 25.0

# Verdict Execution time Memory Grader output
1 Correct 271 ms 18904 KB Output is correct
2 Correct 309 ms 17580 KB Output is correct
3 Correct 265 ms 17096 KB Output is correct
4 Correct 212 ms 16008 KB Output is correct
5 Correct 339 ms 19296 KB Output is correct
6 Correct 273 ms 19980 KB Output is correct
7 Correct 242 ms 20440 KB Output is correct
8 Correct 227 ms 18280 KB Output is correct
9 Correct 223 ms 17140 KB Output is correct
10 Correct 290 ms 17008 KB Output is correct
11 Correct 216 ms 17380 KB Output is correct
12 Correct 198 ms 14400 KB Output is correct
13 Correct 220 ms 16176 KB Output is correct
14 Correct 231 ms 18752 KB Output is correct
15 Correct 232 ms 16312 KB Output is correct
16 Correct 1 ms 340 KB Output is correct
17 Correct 182 ms 8552 KB Output is correct
18 Correct 191 ms 12216 KB Output is correct
19 Correct 1 ms 212 KB Output is correct
20 Correct 1 ms 212 KB Output is correct
21 Correct 345 ms 40128 KB Output is correct
22 Correct 335 ms 40128 KB Output is correct
23 Correct 274 ms 35600 KB Output is correct
24 Correct 273 ms 35696 KB Output is correct
25 Correct 256 ms 36440 KB Output is correct
26 Correct 298 ms 35028 KB Output is correct
27 Correct 329 ms 39908 KB Output is correct
28 Correct 304 ms 38396 KB Output is correct
29 Correct 302 ms 36260 KB Output is correct
30 Correct 299 ms 38192 KB Output is correct
31 Correct 237 ms 35960 KB Output is correct
32 Correct 280 ms 35056 KB Output is correct
33 Correct 297 ms 38380 KB Output is correct
34 Correct 252 ms 36156 KB Output is correct
35 Correct 345 ms 39216 KB Output is correct
36 Correct 41 ms 21512 KB Output is correct
37 Correct 268 ms 31108 KB Output is correct
38 Correct 237 ms 34984 KB Output is correct
39 Correct 85 ms 23360 KB Output is correct
40 Correct 113 ms 24084 KB Output is correct
41 Correct 83 ms 13928 KB Output is correct
42 Correct 93 ms 13440 KB Output is correct
43 Correct 73 ms 13216 KB Output is correct
44 Correct 49 ms 12956 KB Output is correct
45 Correct 55 ms 13580 KB Output is correct
46 Correct 52 ms 12816 KB Output is correct
47 Correct 65 ms 13380 KB Output is correct
48 Correct 53 ms 12712 KB Output is correct
49 Correct 57 ms 13368 KB Output is correct
50 Correct 51 ms 12576 KB Output is correct
51 Correct 52 ms 13152 KB Output is correct
52 Correct 47 ms 12624 KB Output is correct
53 Correct 44 ms 12560 KB Output is correct
54 Correct 45 ms 13060 KB Output is correct
55 Correct 42 ms 12796 KB Output is correct
56 Correct 17 ms 10460 KB Output is correct
57 Correct 40 ms 11416 KB Output is correct
58 Correct 37 ms 11884 KB Output is correct
59 Correct 1 ms 212 KB Output is correct
60 Correct 1 ms 212 KB Output is correct
61 Correct 621 ms 47360 KB Output is correct
62 Correct 532 ms 45916 KB Output is correct
63 Correct 524 ms 44636 KB Output is correct
64 Correct 417 ms 44492 KB Output is correct
65 Correct 435 ms 46152 KB Output is correct
66 Correct 412 ms 44188 KB Output is correct
67 Correct 391 ms 44324 KB Output is correct
68 Correct 370 ms 42344 KB Output is correct
69 Correct 387 ms 45108 KB Output is correct
70 Correct 346 ms 41180 KB Output is correct
71 Correct 316 ms 44488 KB Output is correct
72 Correct 383 ms 41764 KB Output is correct
73 Correct 378 ms 42632 KB Output is correct
74 Correct 341 ms 44496 KB Output is correct
75 Correct 345 ms 43124 KB Output is correct
76 Correct 33 ms 21452 KB Output is correct
77 Correct 250 ms 31380 KB Output is correct
78 Correct 252 ms 35156 KB Output is correct
79 Correct 1 ms 212 KB Output is correct
80 Correct 0 ms 212 KB Output is correct