Submission #1263974

#	Time	Username	Problem	Language	Result	Execution time	Memory
1263974		BlockOG	Arranging Shoes (IOI19_shoes)	C++20	100 / 100	641 ms	32256 KiB

shoes

#include <bits/stdc++.h>

// mrrrow meeow :3
// go play vivid/stasis now! it's free on steam

#define fo(i, a, b) for (auto i = (a); i < (b); i++)
#define of(i, a, b) for (auto i = (b); i-- > (a);)
#define f first
#define s second
#define pb push_back
#define pob pop_back
#define lb lower_bound
#define ub upper_bound
#define be(a) a.begin(), a.end()
using namespace std;

int ____init = [] {
    ios::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);
    return 0;
}();

int bit[200001];

void add(int i, int v) {
    for (i++; i <= 200000; i += i & -i) bit[i] += v;
}

int get(int i) {
    int res = 0;
    for (i++; i > 0; i -= i & -i) res += bit[i];
    return res;
}

long long count_swaps(vector<int> s) {
    long long n = s.size() / 2;

    map<int, set<int>> m;
    fo(i, 0, 2 * n) {
        m[s[i]].insert(i);
        add(i, 1);
    }
    add(0, -1);

    long long res = 0;
    int zero = 0;
    fo(i, 0, n) {
        while (get(zero) != 0) zero++;

        int first_curr = zero;
        int first_other = *m[-s[first_curr]].begin();
        m[s[first_curr]].erase(first_curr);
        m[s[first_other]].erase(first_other);

        if (s[first_curr] > 0) swap(first_curr, first_other);

        cerr << s[first_curr] << ' ' << s[first_other] << endl;

        res += get(first_curr);
        add(first_curr, -1);
        res += get(first_other);
        add(first_other, -1);
    }

    return res;
}

• Subtask 1: 10 / 10
• Subtask 2: 20 / 20
• Subtask 3: 20 / 20
• Subtask 4: 15 / 15
• Subtask 5: 20 / 20
• Subtask 6: 15 / 15