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Submission #1106426

# Submission time Handle Problem Language Result Execution time Memory
1106426 2024-10-30T10:27:03 Z atom Izbori (COCI22_izbori) C++17
40 / 110
 387 ms 8644 KB 
#include "bits/stdc++.h"
// @JASPER'S BOILERPLATE
using namespace std;
using ll = long long;

#ifdef JASPER
#include "debug.h"
#else
#define debug(...) 166
#endif

const int N = 2e5 + 5;
const int B = 450;
int a[N];
int n;

bool sub12() {
    return (n <= 2000);
}

bool sub3() {
    for (int i = 1; i <= n; ++i)
        if (a[i] > 2) return false;
    return true;
}

template <typename T>
struct Fenwick {
    vector <int> f;
    int n;
    Fenwick(int _n) {
        f.resize(_n + 5);
        n = _n;
    }

    void upd(int x, int val) {
        for (; x <= n; x += x & -x)
            f[x] += val;
    }

    int get(int x) {
        int ans = 0;
        for (; x > 0; x -= x & -x)
            ans += f[x];
        return ans;
    }
};

signed main() {
    cin.tie(0) -> sync_with_stdio(0);
    
    #ifdef JASPER
        freopen("in2", "r", stdin);
    #endif

    cin >> n;
    for (int i = 1; i <= n; ++i)
        cin >> a[i];

    if (sub12()) {
        ll ans = 0;
        for (int l = 1; l <= n; ++l) {
            map <int, int> cnt;
            
            pair <int, int> mx = {0, 0};
            for (int r = l; r <= n; ++r) {
                cnt[a[r]]++;
                if (cnt[a[r]] > mx.second) {
                    mx = make_pair(a[r], cnt[a[r]]);
                }
                if (mx.second > (r - l + 1) / 2) {
                    ++ans;
                }
            }
        }

        cout << ans << "\n";
        return 0;
    }

    if (sub3()) {
        vector <int> prf[3];
        for (int i = 1; i <= 2; ++i)
            prf[i].resize(n + 5);

        for (int i = 1; i <= n; ++i) {
            int x = a[i];
            prf[1][i] = prf[1][i - 1] + (x == 1);
            prf[2][i] = prf[2][i - 1] + (x == 2);
        }

        vector <int> vals[3];
        vals[1].push_back(0);
        vals[2].push_back(0);
        for (int i = 1; i <= n; ++i) {
            vals[1].push_back(2 * prf[1][i] - i);
            vals[2].push_back(2 * prf[2][i] - i);
        }

        sort(vals[1].begin(), vals[1].end());
        vals[1].resize(unique(vals[1].begin(), vals[1].end()) - vals[1].begin());
        sort(vals[2].begin(), vals[2].end());
        vals[2].resize(unique(vals[2].begin(), vals[2].end()) - vals[2].begin());

        auto get = [&] (int x, int t) {
            return (int) (lower_bound(vals[t].begin(), vals[t].end(), x) - vals[t].begin() + 1);
        };

        Fenwick <int> f1(n), f2(n);
        ll ans = 0;
        f1.upd(get(0, 1), 1);
        f2.upd(get(0, 2), 1);
        for (int r = 1; r <= n; ++r) {
            int x1 = get(2 * prf[1][r] - r, 1);
            ans += f1.get(x1 - 1);
            f1.upd(x1, 1);

            int x2 = get(2 * prf[2][r] - r, 2);
            ans += f2.get(x2 - 1);
            f2.upd(x2, 1);
        }

        cout << ans << "\n";
        return 0;
    }

    vector <int> vals;
    for (int i = 1; i <= n; ++i)
        vals.push_back(a[i]);

    sort(vals.begin(), vals.end());
    vals.resize(unique(vals.begin(), vals.end()) - vals.begin());

    int sz = (int) vals.size();
    vector <int> cnt(sz, 0);
    for (int i = 1; i <= n; ++i) {
        a[i] = (int) (lower_bound(vals.begin(), vals.end(), a[i]) - vals.begin());
        cnt[a[i]]++;
    }

    vector <bool> heavy(sz, false);
    for (int i = 0; i < sz; ++i) {
        if (cnt[i] >= B)
            heavy[i] = true;
    }

    ll ans = 0;
    // processing light queries: all elements appear less than sqrt(n)
    cnt.clear();
    for (int i = 1; i <= n; ++i) {
        int mx = 0;
        for (int j = i; j <= n && (j - i + 1) / 2 < B; ++j) {
            if (!heavy[a[j]]) {
                cnt[a[j]]++;
                if (cnt[a[j]] > mx) mx = cnt[a[j]];
                if (mx > (j - i + 1) / 2) ++ans;
            }
        }

        for (int j = i; j <= n && (j - i + 1) / 2 < B; ++j)
            if (!heavy[a[j]]) cnt[a[j]]--;
    }

    // processing heavy queries: all elements appear at least sqrt(n)
    for (int x = 0; x < sz; ++x) {
        if (heavy[x]) {
            auto get = [&] (int _x) { return _x + n; };

            vector <int> prf(n + 5);
            for (int i = 1; i <= n; ++i)
                prf[i] = prf[i - 1] + (a[i] == x? 1 : -1);

            vector <int> f(2 * n + 5, 0);
            f[get(0)]++;
            ll sum = 0;
            for (int i = 1; i <= n; ++i) {
                if (prf[i] > 0)
                    sum += cnt[get(prf[i] - 1)];
                else    
                    sum -= cnt[get(prf[i])];
                ans += sum;
                cnt[get(prf[i])]++;
            }
        }
    }

    cout << ans << "\n";

    
    return 0;
}

Subtask #1
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 336 KB Output is correct
2 Correct 1 ms 336 KB Output is correct
3 Correct 1 ms 336 KB Output is correct
4 Correct 2 ms 336 KB Output is correct
5 Correct 1 ms 336 KB Output is correct
6 Correct 1 ms 336 KB Output is correct

Subtask #2
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 336 KB Output is correct
2 Correct 1 ms 336 KB Output is correct
3 Correct 1 ms 336 KB Output is correct
4 Correct 2 ms 336 KB Output is correct
5 Correct 1 ms 336 KB Output is correct
6 Correct 1 ms 336 KB Output is correct
7 Correct 51 ms 336 KB Output is correct
8 Correct 1 ms 336 KB Output is correct
9 Correct 34 ms 336 KB Output is correct
10 Correct 36 ms 336 KB Output is correct
11 Correct 33 ms 336 KB Output is correct
12 Correct 34 ms 336 KB Output is correct
13 Correct 34 ms 336 KB Output is correct
14 Correct 36 ms 336 KB Output is correct
15 Correct 34 ms 336 KB Output is correct
16 Correct 34 ms 336 KB Output is correct
17 Correct 9 ms 336 KB Output is correct

Subtask #3
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 22 ms 4276 KB Output is correct
2 Correct 32 ms 5308 KB Output is correct
3 Correct 17 ms 3268 KB Output is correct
4 Correct 30 ms 5564 KB Output is correct
5 Correct 29 ms 5820 KB Output is correct
6 Correct 33 ms 6068 KB Output is correct
7 Correct 31 ms 6068 KB Output is correct
8 Correct 32 ms 6076 KB Output is correct
9 Correct 32 ms 6068 KB Output is correct
10 Correct 35 ms 6244 KB Output is correct
11 Correct 39 ms 6076 KB Output is correct

Subtask #4
0 / 70.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 336 KB Output is correct
2 Correct 1 ms 336 KB Output is correct
3 Correct 1 ms 336 KB Output is correct
4 Correct 2 ms 336 KB Output is correct
5 Correct 1 ms 336 KB Output is correct
6 Correct 1 ms 336 KB Output is correct
7 Correct 51 ms 336 KB Output is correct
8 Correct 1 ms 336 KB Output is correct
9 Correct 34 ms 336 KB Output is correct
10 Correct 36 ms 336 KB Output is correct
11 Correct 33 ms 336 KB Output is correct
12 Correct 34 ms 336 KB Output is correct
13 Correct 34 ms 336 KB Output is correct
14 Correct 36 ms 336 KB Output is correct
15 Correct 34 ms 336 KB Output is correct
16 Correct 34 ms 336 KB Output is correct
17 Correct 9 ms 336 KB Output is correct
18 Correct 22 ms 4276 KB Output is correct
19 Correct 32 ms 5308 KB Output is correct
20 Correct 17 ms 3268 KB Output is correct
21 Correct 30 ms 5564 KB Output is correct
22 Correct 29 ms 5820 KB Output is correct
23 Correct 33 ms 6068 KB Output is correct
24 Correct 31 ms 6068 KB Output is correct
25 Correct 32 ms 6076 KB Output is correct
26 Correct 32 ms 6068 KB Output is correct
27 Correct 35 ms 6244 KB Output is correct
28 Correct 39 ms 6076 KB Output is correct
29 Runtime error 387 ms 8644 KB Execution killed with signal 11
30 Halted 0 ms 0 KB -