Submission #1185741

#	Time	Username	Problem	Language	Result	Execution time	Memory
1185741		nikaa123	Arranging Shoes (IOI19_shoes)	C++20	0 / 100	2 ms	2628 KiB

shoes

#include "shoes.h"
#include <bits/stdc++.h>
#define pb push_back
using namespace std;

const int N = 1e5 + 5;

int t[4 * N];
int fix[N];
vector<vector<int>> v(N);

void update(int node, int tl, int tr, int pos) {
	if (tl == tr) {
		t[node]++;
		return;
	}
	int mid = (tl + tr) / 2;
	if (pos <= mid) {
		update(node * 2, tl, mid, pos);
	} else {
		update(node * 2 + 1, mid + 1, tr, pos);
	}
	t[node] = t[node * 2] + t[node * 2 + 1];
}

int getsum(int node, int tl, int tr, int l, int r) {
	if (l > r) return 0;
	if (tl == l && tr == r) {
		return t[node];
	}
	int mid = (tl + tr) / 2;
	return getsum(node * 2, tl, mid, l, min(r, mid)) +
	       getsum(node * 2 + 1, mid + 1, tr, max(mid + 1, l), r);
}

long long count_swaps(std::vector<int> s) {
	int n = s.size();
	s.insert(s.begin(), 0);
	for (int i = 1; i <= n; i++) {
		s[i] += n / 2;
		v[s[i]].pb(i);
	}

	long long op = 0;
	for (int i = 1; i <= n; i++) {
		if (fix[i]) continue;
		int a = s[i];
		int b = (a <= n / 2) ? a + n / 2 : a - n / 2;

		int l = 0, r = v[b].size() - 1;
		int ib = -1;
		while (l <= r) {
			int mid = (l + r) / 2;
			if (v[b][mid] > i) {
				ib = v[b][mid];
				r = mid - 1;
			} else {
				l = mid + 1;
			}
		}
		int shift = getsum(1, 1, n, i + 1, ib - 1);
		op += (ib - i - 1 - shift);
		if (a > n / 2) op++;

		update(1, 1, n, ib);
		fix[ib] = 1;
	}
	return op;
}

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