Submission #426632

#	Time	Username	Problem	Language	Result	Execution time	Memory
426632		saleh	Arranging Shoes (IOI19_shoes)	C++17	100 / 100	822 ms	158096 KiB

shoes

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

#define ft first
#define sd second

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, deque<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()) {
			if (s[i] > 0) vec.push_back({v[-s[i]].front(), i});
			else vec.push_back({i, v[-s[i]].front()});
			v[s[i]].pop_back();
			v[-s[i]].pop_front();
		}
	}
//	for (auto i : vec) cout << i.ft << ' ' << i.sd << endl;
	sort(vec.begin(), vec.end(), [](pii x, pii y) { return x.ft + x.sd < y.ft + y.sd; });
	for (auto i : vec) {
//		cout << i.ft << ' ' << i.sd << endl;
		a[i.ft] = cnt++;
		a[i.sd] = cnt++;
	}
	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: 20 / 20
• Subtask 3: 20 / 20
• Subtask 4: 15 / 15
• Subtask 5: 20 / 20
• Subtask 6: 15 / 15