Submission #230205

#	Time	Username	Problem	Language	Result	Execution time	Memory
230205		Masterdan	Arranging Shoes (IOI19_shoes)	C++14	100 / 100	651 ms	50080 KiB

shoes

#include <bits/stdc++.h>
#define MAX 1e9+7
#define MIN -1
#define all(a)  a.begin (),a.end ()
#define pb  push_back
#define mp  make_pair
#define mem(a, c) memset(a, c, sizeof(a))
#define F first
#define S second
#define PI 3.141592653589
#define SMAX 1e18+7
using namespace std;
typedef vector <int> vi;
typedef pair<int, int> ii;
typedef vector <ii> vii;
typedef long long ll;
typedef double db;
int tree[800200];

void update(int node, int in, int fin, int pos) {
  if (pos < in || pos >= fin) {
    return;
  }
  tree[node] += 1;
  if (in + 1 != fin) {
    int mid = in + (fin - in) / 2;
    update(2 * node + 1, in, mid, pos);
    update(2 * node + 2, mid, fin, pos);
  }
}

ll query(int node, int in, int fin, int l, int r) {
  if (fin <= l || r <= in) {
    return 0;
  }
  if (l <= in && fin <= r) {
    return tree[node];
  }
  int mid = in + (fin - in) / 2;
  return query(2 * node + 1, in, mid, l, r) +query(2 * node + 2, mid, fin, l, r);
}

ll count_swaps(vi a) {
  int n = a.size() / 2;
  ll ans = 0;
  map<int, vi> last;
  vi pr(2 * n, -1);
  for (int i = 2 * n - 1; i >= 0; i--) {
    last[a[i]].pb(i);
  }
  for (int i = 0; i < 2 * n; i++) {
    if (pr[i] != -1)
      continue;
    pr[i] = last[-a[i]].back();
    last[-a[i]].pop_back();
    last[a[i]].pop_back();
    ans += abs(pr[i] - i) - 1;
    if ((pr[i] > i) != (a[pr[i]] > a[i])) {
      ans++;
    }
    pr[pr[i]] = i;
  }
  vector<vi> q;
  for (int i = 0; i < 2 * n; i++) {
    q.pb({i});
    if (pr[i] > i) {
      q.pb({i, pr[i] + 1, -1});
      q.pb({pr[i], pr[i] + 1, 1});
    }
  }
  mem(tree, 0);
  sort(all(q));
  for (int i=0;i<q.size ();i++) {
    vi v3=q[i];
    if (v3.size() == 1) {
      update(0, 0, 2 * n, pr[v3[0]]);
    } else {
      int x = query(0, 0, 2 * n, v3[1], 2 * n);
      ans -= x * v3[2];
    }
  }
  return ans;
}

/*
using namespace std;

int main() {
	int n;
	assert(1 == scanf("%d", &n));
	vector<int> S(2 * n);
	for (int i = 0; i < 2 * n; i++)
		assert(1 == scanf("%d", &S[i]));
	fclose(stdin);

	long long result = count_swaps(S);

	printf("%lld\n", result);
	fclose(stdout);
	return 0;
}
*/

Compilation message (stderr)

shoes.cpp: In function 'll count_swaps(vi)':
shoes.cpp:73:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for (int i=0;i<q.size ();i++) {
                ~^~~~~~~~~~

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