Submission #766443

#	Time	Username	Problem	Language	Result	Execution time	Memory
766443		Chal1shkan	Untitled (POI11_rot)	C++14	100 / 100	142 ms	11264 KiB

Main

//Bismillahir-Rahmanir-Rahim
 
# include <bits/stdc++.h>
 
# define pb push_back
# define ff first
# define ss second
# define nl "\n"
# define sz(x) ((int)(x).size())
# define all(x) (x).begin(), (x).end()
# define deb(x) cerr << #x  << " = " << x << endl; 
# define pll pair <ll, ll>
# define pii pair <int, int>
 
typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;
 
const ll maxn = 2e5 + 2;
const ll inf = 2e18 + 0;
const ll mod = 1e9 + 7;
const ll dx[] = {-1, 1, 0, 0};
const ll dy[] = {0, 0, -1, 1};
 
using namespace std;
 
int n, nv;
int L[maxn * 2];
int R[maxn * 2];
int sz[maxn * 2];
int cnt[maxn * 2];
ll t[maxn], ans;
 
void upd (int id, int x)
{
    for (; id < maxn; id += (id & (-id)))
    {
        t[id] += x;
    }
}
 
int get (int id)
{
    int res = 0;
    for (; id >= 1; id -= (id & (-id)))
    {
        res += t[id];
    }
    return res;
}
 
int rec ()
{
    int x; cin >> x;
    if (!x)
    {
        int v = ++nv;
        L[v] = rec ();
        R[v] = rec ();
        sz[v] = sz[L[v]] + sz[R[v]] + 1;
        cnt[v] = cnt[L[v]] + cnt[R[v]];
        return v;
    }
    sz[x] = 1, cnt[x] = 1;
    return x;
}
 
void add (int v)
{
    if (v <= n) upd(v, 1);
    else add(L[v]), add(R[v]);
}
 
void clr (int v)
{
    if (v <= n) upd(v, -1);
    else clr(L[v]), clr(R[v]);
}
 
ll calc (int v)
{
    if (v <= n) return get(v);
    return calc(L[v]) + calc(R[v]);
}
 
void dfs (int v = n + 1, bool keep = 1)
{
    if (v <= n)
    {
        add(v);
    }
    else
    {
        if (sz[L[v]] < sz[R[v]])
        {
            swap(L[v], R[v]);
        }
        dfs(R[v], 0);
        dfs(L[v], 1);
        ll inv = calc(R[v]);
      //  cout << v << ' ' << inv << ' ' << cnt[L[v]] << ' ' << cnt[R[v]] << nl;
        ans += min(1LL * inv, cnt[L[v]] * 1LL * cnt[R[v]] - inv);
        add(R[v]);
    }
    if (!keep)
    {
        clr(v);
    }
}
 
void ma1n (/* SABR */)
{
    cin >> n;
    nv = n;
    rec ();
    dfs ();
    cout << ans;
}
 
signed main()
{
    ios::sync_with_stdio(false);
    cin.tie(0); cout.tie(0);
//  freopen("file.in", "r", stdin);
//  freopen("file.out", "w", stdout);
    int ttt = 1;
//  cin >> ttt;
    for (int test = 1; test <= ttt; ++test)
    {
//      cout << "Case " << test << ":" << '\n';
        ma1n();
    }
    return 0;
}
 
// 998batrr | BbIWEJI 3A TObOU!!!
// tourist  | BbIWEJI 3A TObOU!!!

• Subtask 1: 9 / 9
• Subtask 2: 9 / 9
• Subtask 3: 9 / 9
• Subtask 4: 9 / 9
• Subtask 5: 9 / 9
• Subtask 6: 9 / 9
• Subtask 7: 9 / 9
• Subtask 8: 9 / 9
• Subtask 9: 9 / 9
• Subtask 10: 9 / 9
• Subtask 11: 10 / 10