Submission #1192937

#	Time	Username	Problem	Language	Result	Execution time	Memory
1192937		Lemser	Seats (IOI18_seats)	C++20	33 / 100	992 ms	126268 KiB

seats

#include "seats.h"
#include <bits/stdc++.h>
#pragma GCC optimize("Ofast")
#pragma GCC target("avx2")
#pragma GCC target("popcnt")
using namespace std;

using ll = long long;
using ull = unsigned long long;
using lld = long double;
using ii = pair<int,int>;
using pll = pair<ll, ll>;

using vi = vector<int>;
using vll = vector<ll>;
using vii = vector<ii>;
using vpll = vector<pll>;
using vlld = vector<lld>;

#define all(x) x.begin(),x.end()
#define lsb(x) x&(-x)
#define gcd(a,b) __gcd(a,b)
#define sz(x) (int)x.size()
#define mp make_pair
#define pb push_back
#define fi first
#define se second
#define fls cout.flush()

#define fore(i, l, r) for (auto i = l; i < r; i++)
#define fo(i, n) fore (i, 0, n)
#define forex(i, r, l) for (auto i = r-1; i >= l; i--)
#define ffo(i, n) forex (i, n, 0)

bool cmin(ll &a, ll b) { if (b < a) { a=b; return 1; } return 0; }
bool cmax(ll &a, ll b) { if (b > a) { a=b; return 1; } return 0; }

void valid(ll in) { cout<<((in)?"YES\n":"NO\n"); }
ll lcm(ll a, ll b) { return (a/gcd(a,b))*b; }
ll gauss(ll n) { return (n*(n+1))/2; }

const ll INF = 1e18;

struct SegTree {
  struct Node {
    ll mn, cnt;
    
    Node ( ) {  }
    Node (ll mn, ll cnt): mn(mn), cnt(cnt) {  }

    Node operator +(const Node &o) {
      return {
        min(mn, o.mn),
        (mn <= o.mn ? cnt : 0) +
        (o.mn <= mn ? o.cnt : 0)
      };
    };
  };

  Node IDEM = {0, 1};
  vector<Node> st;
  vll lz;
  ll n;

  SegTree () {  }
  SegTree (ll n): st(4*n+4, IDEM), lz(4*n+4,0), n(n) {  }

  void push (ll id, ll l, ll r) {
    st[id].mn += lz[id];
    if (l != r) {
      lz[id*2] += lz[id];
      lz[id*2+1] += lz[id];
    }
    lz[id] = 0;
  }

  void update (ll l, ll r, ll c) { update(1, 0, n-1, l, r, c); }
  void update (ll id, ll l, ll r, ll i, ll j, ll c) {
    push(id, l, r);
    if (r < i || j < l) return;
    if (i <= l && r <= j) {
      lz[id] += c;
      push(id, l, r);
      return;
    }
    ll m = (l+r)/2;
    update(id*2, l, m, i, j, c);
    update(id*2+1, m+1, r, i, j, c);
    st[id] = st[id*2] + st[id*2+1];
  }
  
};

const int N = 1e6 + 7;
ll a[N], h, w, pos[N];
SegTree st;

void upd (ll i, ll j, ll c) {
  if (j < i) swap(i, j);
  ll A = (i == -1 ? w : a[i]), B = (j == w ? w : a[j]);
  if (A > B) swap(A, B);
  st.update(A, B-1, +c);
}

void give_initial_chart(int H, int W, std::vector<int> R, std::vector<int> C) {
  h = H;
  w = W;
  st = SegTree(W);
  fo (i, W) a[C[i]] = i;
  fo (i, W) pos[i] = C[i];
  fo (i, W+1) {
    upd (i-1, i, +1);
  }
}

int swap_seats(int x, int y) {
  ll i = pos[x], j = pos[y];
  upd(i-1, i, -1);
  upd(i, i+1, -1);
  if (j != i+1) upd(j-1, j, -1);
  if (j+1 != i) upd(j, j+1, -1);
  swap(a[i], a[j]);
  swap(pos[x], pos[y]);
  upd(i-1, i, +1);
  upd(i, i+1, +1);
  if (j != i+1) upd(j-1, j, +1);
  if (j+1 != i) upd(j, j+1, +1);
  auto ans = st.st[1];
  return (ans.mn == 2 ? ans.cnt : 0);
}

• Subtask 1: 0 / 5
• Subtask 2: 0 / 6
• Subtask 3: 0 / 20
• Subtask 4: 0 / 6
• Subtask 5: 33 / 33
• Subtask 6: 0 / 30