Submission #711945

#	Time	Username	Problem	Language	Result	Execution time	Memory
711945		JANCARAPAN	Arranging Shoes (IOI19_shoes)	C++17	100 / 100	120 ms	22604 KiB

shoes

#include <bits/stdc++.h>
using namespace std;
//#define int long long   
#define ll long long
#define fi first
#define se second
#define pb push_back
#define all(a) (a).begin(), (a).end()
#define sz(a) (long long) a.size()
#define endl '\n'

#define dbg(a) cerr << #a << " = " << a << endl;
#define print(a) for (auto x : a) cerr << x << " "; cerr << endl;

const long long INF = 1e18, MOD = 1e9+7;

struct segTree {
  int size = 1;
  vector<int> t;
  void init(int n) {
    while (size < n) size *= 2;
    t.assign(2 * size, 0LL);
  }
  int merge(int a, int b) {
    return a + b;
  }
  void set(int i, int x, int lx, int rx, int k) {
    if (rx - lx == 1) {
      t[x] += k;
      return;
    }
    int m = (lx + rx) / 2;
    if (i < m) {
      set(i, 2 * x + 1, lx, m, k);
    }
    else {
      set(i, 2 * x + 2, m, rx, k);
    }
    t[x] = merge(t[2 * x + 1], t[2 * x + 2]);
  }
  void set(int i, int k) {
    set(i, 0, 0, size, k);
  }
  int calc(int l, int r, int x, int lx, int rx) {
    if (lx >= l && rx <= r) {
      return t[x];
    }
    if (lx >= r || rx <= l) {
      return 0;
    }
    int m = (lx + rx) / 2;
    auto m0 = calc(l, r, 2 * x + 1, lx, m);
    auto m1 = calc(l, r, 2 * x + 2, m, rx);
    return merge(m0, m1);
  }
  int calc(int l, int r) {
    return calc(l, r, 0, 0, size);
  }
};

ll count_swaps(vector<int> tmp) {
  int n = sz(tmp);
  vector pos(n + 1, vector<int>()), neg(n + 1, vector<int>());
  
  for (int i = 0; i < n; i++) {
    if (tmp[i] > 0) {
      pos[tmp[i]].pb(i);
    }
    else {
      neg[abs(tmp[i])].pb(i);
    }
  }
  // ara formo parelles
  vector<int> other;
  vector<int> a(n), add;
  
  for (int i = 1; i <= n; i++) {
    for (int j = 0; j < sz(pos[i]); j++) {
      a[pos[i][j]] = a[neg[i][j]] = sz(other);
      other.emplace_back(max(pos[i][j], neg[i][j]));
      add.emplace_back(pos[i][j] < neg[i][j]);
    }
  }
  
  segTree st;
  st.init(n);
  
  ll ans = 0;
  for (int i = 0; i < n; i++) {
    if (other[a[i]] == i) {
      continue;
    }
    ans += other[a[i]] - i - 1 + add[a[i]];
    ans -= st.calc(i, other[a[i]]);
    st.set(other[a[i]], 1);
  }
  
  return ans;
  
}

//signed main() {
  //cout << count_swaps({2, 1, -1, -2}) << endl;
//}

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