Submission #748182

#	Time	Username	Problem	Language	Result	Execution time	Memory
748182		MinaRagy06	Swap Swap Sort (CCO21_day1problem1)	C++17	11 / 25	5016 ms	176272 KiB

Main

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace std;
using namespace __gnu_pbds;
typedef int64_t ll;

tree<pair<int, int>, null_type, less<pair<int, int>>, rb_tree_tag, tree_order_statistics_node_update> invs;
set<pair<int, int>> s;
vector<pair<int, int>> pairs;
vector<pair<int, int>> check[100'005];
int val[2'000'005], q[1'000'005], a[100'005], p[100'005];
vector<int> frq[100'005];

int main() {
    ios_base::sync_with_stdio(0), cin.tie(0);
    int n, k, m;
    cin >> n >> k >> m;
    for (int i = 0; i < k; i++) {
        p[i] = i + 1;
    }
    ll ans = 0;
    for (int i = 0; i < n; i++) {
        cin >> a[i];
        frq[a[i]].push_back(i);
        ans += invs.size() - invs.order_of_key({a[i] + 1, 0});
        invs.insert({a[i], i});
    }
    for (int i = 0; i < m; i++) {
        cin >> q[i];
        q[i]--;
        s.insert({p[q[i]], p[q[i] + 1]});
        swap(p[q[i]], p[q[i] + 1]);
        s.insert({p[q[i]], p[q[i] + 1]});
    }
    for (auto i : s) pairs.push_back(i);
    for (int i = 0; i < pairs.size(); i++) {
        check[pairs[i].first].push_back({pairs[i].second, i});
    }
    assert(pairs.size() <= 2'000'005);
    for (int i = 1; i <= k; i++) {
        for (auto &[j, idx] : check[i]) {
            if (frq[i].empty() || frq[j].empty()) continue;
            if (frq[i].size() <= frq[j].size()) {
                int prv = 0;
                for (auto l : frq[i]) {
                    val[idx] += frq[j].size() - (prv = lower_bound(frq[j].begin() + prv, frq[j].end(), l) - frq[j].begin());
                }
            } else {
                int prv = 0;
                for (auto l : frq[j]) {
                    val[idx] += (prv = lower_bound(frq[i].begin() + prv, frq[i].end(), l) - frq[i].begin());
                }
            }
        }
    }
    for (int i = 0; i < k; i++) {
        p[i] = i + 1;
    }
    for (int i = 0; i < m; i++) {
        ans += val[lower_bound(pairs.begin(), pairs.end(), make_pair(p[q[i]], p[q[i] + 1])) - pairs.begin()];
        swap(p[q[i]], p[q[i] + 1]);
        ans -= val[lower_bound(pairs.begin(), pairs.end(), make_pair(p[q[i]], p[q[i] + 1])) - pairs.begin()];
        cout << ans << '\n';
    }
    return 0;
}

Compilation message (stderr)

Main.cpp: In function 'int main()':
Main.cpp:37:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   37 |     for (int i = 0; i < pairs.size(); i++) {
      |                     ~~^~~~~~~~~~~~~~

• Subtask 1: 3 / 3
• Subtask 2: 3 / 3
• Subtask 3: 5 / 5
• Subtask 4: 0 / 14