Submission #576295

#	Time	Username	Problem	Language	Result	Execution time	Memory
576295		eecs	Swap Swap Sort (CCO21_day1problem1)	C++17	25 / 25	2863 ms	85808 KiB

Main

#include <bits/stdc++.h>
using namespace std;

const int maxn = 100010;
int n, m, q, a[maxn], p[maxn];
vector<int> V[maxn];

namespace BIT {
int c[maxn];

void add(int p, int v) {
    for (; p <= m; p += p & -p) c[p] += v;
}

int query(int p) {
    int s = 0;
    for (; p; p -= p & -p) s += c[p];
    return s;
}
} // namespace BIT

int main() {
    ios::sync_with_stdio(0), cin.tie(0);
    cin >> n >> m >> q;
    for (int i = 1; i <= n; i++) {
        cin >> a[i], V[a[i]].push_back(i);
    }
    iota(p + 1, p + m + 1, 1);
    long long ans = 0;
    for (int i = n; i; i--) {
        ans += BIT::query(a[i] - 1), BIT::add(a[i], 1);
    }
    auto solve = [&](int x, int y) {
        static map<pair<int, int>, long long> mp;
        if (mp.count({x, y})) return mp[{x, y}];
        long long s = 0;
        if (V[x].size() < V[y].size()) {
            for (int i : V[x]) {
                s += V[y].end() - lower_bound(V[y].begin(), V[y].end(), i);
            }
        } else {
            for (int i : V[y]) {
                s += lower_bound(V[x].begin(), V[x].end(), i) - V[x].begin();
            }
        }
        return mp[{x, y}] = s;
    };
    while (q--) {
        int k;
        cin >> k;
        ans += 2 * solve(p[k], p[k + 1]) - 1LL * V[p[k]].size() * V[p[k + 1]].size();
        cout << ans << "\n", swap(p[k], p[k + 1]);
    }
    return 0;
}

• Subtask 1: 3 / 3
• Subtask 2: 3 / 3
• Subtask 3: 5 / 5
• Subtask 4: 14 / 14