Submission #835313

#	Time	Username	Problem	Language	Result	Execution time	Memory
835313		VMaksimoski008	Arranging Shoes (IOI19_shoes)	C++14	85 / 100	52 ms	7800 KiB

shoes

#include <bits/stdc++.h>

#define pb push_back
#define eb emplace_back
#define sz(x) (int)x.size()
#define all(x) x.begin(), x.end()
#define uniq(x) x.erase(unique(all(x)), x.end())
#define rall(x) x.rbegin(), x.rend()
//#define int long long

using namespace std;

using ll = long long;
using ull = unsigned long long;
using ld = long double;
using pii = pair<int, int>;
using pll = pair<ll, ll>;

const int mod = 1e9 + 7;
const int LOG = 20;
const int maxn = 1e5 + 5;
const double eps = 1e-9;

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

int64_t count_swaps(vector<int> S) {
    
    int n = sz(S) / 2;
    set<int> diff;

    for(int &x : S) diff.insert(abs(x));

    if(diff.size() == 1) {
        ll ans = 0;

        int curr = 0;
        for(int i=0; i<sz(S); i++) {
            if(S[i] < 0) {
                ans += 1ll * abs(i - curr);
                curr += 2;
            }
        }

        return ans;
    }

    if(n <= 1000) {
        ll ans = 0;

        vector<bool> vis(2*n, 0);

        for(int i=0; i<2*n; i++) {
            if(vis[i]) continue;
            vis[i] = true;
            int res = 0;
            for(int j=i+1; j<2*n; j++) {
                if(vis[j]) res--;
                if(vis[j]) continue;
                if(S[i] + S[j] != 0) continue;
                if(S[i] < 0) res += (j - i - 1);
                else res += (j - i);
                vis[j] = true;
                ans += res;
                //cout << i+1 << " " << j+1 << ": " << res << '\n';
                break;
            }
        }

        return ans;
    }

    ll ans = 1ll * n * (n - 1);
    ans /= 2;
    return ans;
}

// int32_t main() {
//     setIO();

//     int n;
//     cin >> n;
//     vector<int> v(2*n);
//     for(int &x : v) cin >> x;

//     cout << count_swaps(v) << '\n';
//     return 0;
// }

• Subtask 1: 10 / 10
• Subtask 2: 20 / 20
• Subtask 3: 20 / 20
• Subtask 4: 15 / 15
• Subtask 5: 20 / 20
• Subtask 6: 0 / 15