Submission #426620

#	Time	Username	Problem	Language	Result	Execution time	Memory
426620		saleh	Arranging Shoes (IOI19_shoes)	C++17	10 / 100	2 ms	1060 KiB

shoes

#include "shoes.h"//
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/detail/standard_policies.hpp>


using namespace std;
using namespace __gnu_pbds;

typedef pair<int, int> pii;
typedef tree<int, null_type, less<int>, rb_tree_tag, tree_order_statistics_node_update> ordered_set;

const int MAXN = 100 * 1000 + 23;
map<int, vector<int>> v;
ordered_set t;
vector<pii> vec;

long long count_swaps(vector<int> s) {
	int n = s.size() / 2, cnt = 0, a[MAXN << 1];
	long long ans = 0;
	for (int i = 0; i < (n << 1); i++) {
		v[s[i]].push_back(i);
		if (!v[-s[i]].empty()) {
			a[i] = cnt++;
			a[v[-s[i]].back()] = cnt++;
			if (s[i] > 0) swap(a[i], a[v[-s[i]].back()]);
			v[s[i]].pop_back();
			v[-s[i]].pop_back();
		}
	}
	for (int i = 0; i < (n << 1); i++) {
	//	cout << a[i] << ' ';
		ans += t.size() - t.order_of_key(a[i]);
		t.insert(a[i]);
	}//cout << endl;
	return ans;
}

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

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