Submission #785161

#	Time	Username	Problem	Language	Result	Execution time	Memory
785161		acatmeowmeow	Arranging Shoes (IOI19_shoes)	C++14	45 / 100	38 ms	9796 KiB

shoes

#include "shoes.h"
#include <bits/stdc++.h>

using namespace std;

const int N = 1e5;
vector<int> lef, rig[N + 5];
int tree[2*N + 5];

void update(int n, int k, int v) {
	for (; k <= n; k += k&-k) tree[k] += v; 
}

int query(int k) {
	int sum = 0;
	for (; k; k -= k&-k) sum += tree[k];
	return sum;
}

long long count_swaps(std::vector<int> s) {
	ios::sync_with_stdio(false);
	cin.tie(nullptr);
	int n = s.size()/2;
	s.insert(s.begin(), 0);
	for (int i = 1; i <= 2*n; i++) {
		if (s[i] < 0) lef.push_back(i);
		else rig[s[i]].push_back(i);
	}
	sort(lef.begin(), lef.end());
	for (int i = 1; i <= N; i++) sort(rig[i].begin(), rig[i].end(), greater<int>());
	int index = 0;
   	long long ans = 0;
	for (auto&i : lef) {
		index++;
		int new_i = i + query(2*n) - query(i);
		ans += (long long)new_i - index;
		update(2*n, i, 1);

		index++;
		int j = rig[-s[i]].back();
		rig[-s[i]].pop_back();
		int new_j = j + query(2*n) - query(j);
		ans += (long long)new_j - index;
		update(2*n, j, 1);
	}
	return ans;
}

/*signed main() {
	int n;
	cin >> n;
	vector<signed> arr(2*n);
	for (int i = 0; i < 2*n; i++) cin >> arr[i];
	cout << count_swaps(arr) << '\n';
	return 0;
}*/

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