Submission #883234

#	Time	Username	Problem	Language	Result	Execution time	Memory
883234		borisAngelov	Izbori (COCI22_izbori)	C++17	40 / 110	3048 ms	12720 KiB

Main

#include <bits/stdc++.h>

using namespace std;

const int maxn = 200005;

int n;

int a[maxn];

vector<int> byPosition[maxn];

void read()
{
    cin >> n;

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

void compress()
{
    vector<pair<int, int>> v;

    for (int i = 1; i <= n; ++i)
    {
        v.push_back(make_pair(a[i], i));
    }

    sort(v.begin(), v.end());

    int maxNumber = 0;

    for (int i = 0; i < v.size(); ++i)
    {
        if (i == 0 || v[i].first != v[i - 1].first)
        {
            ++maxNumber;
        }

        a[v[i].second] = maxNumber;
    }
}

int b[maxn];
int pref[maxn];

struct FenwickTree
{
    int tree[2 * maxn];

    void reset()
    {
        for (int i = 1; i <= 2 * n; ++i)
        {
            tree[i] = 0;
        }
    }

    void update(int pos, int val)
    {
        for (int i = pos; i <= 2 * n; i += (i & (-i)))
        {
            tree[i] += val;
        }
    }

    int query(int pos)
    {
        int result = 0;

        for (int i = pos; i >= 1; i -= (i & (-i)))
        {
            result += tree[i];
        }

        return result;
    }
};

FenwickTree tree;

void solve()
{
    compress();

    for (int i = 1; i <= n; ++i)
    {
        byPosition[a[i]].push_back(i);
    }

    long long ans = 0;

    for (int i = 1; i <= n; ++i)
    {
        if (byPosition[i].empty() == true)
        {
            continue;
        }

        for (int j = 1; j <= n; ++j)
        {
            b[j] = -1;
        }

        for (int j = 0; j < byPosition[i].size(); ++j)
        {
            b[byPosition[i][j]] = +1;
        }

        tree.reset();
        tree.update(n, +1);

        for (int j = 1; j <= n; ++j)
        {
            pref[j] = pref[j - 1] + b[j];
            tree.update(pref[j] + n, +1);
            ans += tree.query(pref[j] + n - 1);
        }
    }

    cout << ans << endl;
}

void fastIO()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
}

int main()
{
    fastIO();

    read();
    solve();

    return 0;
}

Compilation message (stderr)

Main.cpp: In function 'void compress()':
Main.cpp:36:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   36 |     for (int i = 0; i < v.size(); ++i)
      |                     ~~^~~~~~~~~~
Main.cpp: In function 'void solve()':
Main.cpp:108:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  108 |         for (int j = 0; j < byPosition[i].size(); ++j)
      |                         ~~^~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 10 / 10
• Subtask 2: 15 / 15
• Subtask 3: 15 / 15
• Subtask 4: 0 / 70