Submission #929029

#	Time	Username	Problem	Language	Result	Execution time	Memory
929029		AtabayRajabli	Arranging Shoes (IOI19_shoes)	C++17	100 / 100	148 ms	140204 KiB

shoes

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

const int MX = 2e5 + 5;
int a[MX], used[MX];

void add(int ind, int x)
{
	ind++;
	while(ind < MX)
	{
		a[ind] += x;
		ind += ind & -ind;
	}
}

int get(int ind)
{
	ind++;
	int r = 0;
	while(ind > 0)
	{
		r += a[ind];
		ind -= ind & -ind;
	}
	return r;
}

long long count_swaps(vector<int> s) {
	int N = s.size() / 2;

	queue<int> p[N + 1], n[N + 1];
	for(int i = 0; i < N * 2; i++)
	{
		if(s[i] > 0)p[s[i]].push(i + 1);
		else n[-s[i]].push(i + 1);
	}

	long long ans = 0;
	for(int i = 0; i < N * 2; i++)
	{
		if(used[i + 1])continue;

		int x = p[abs(s[i])].front();
		int y = n[abs(s[i])].front();
		p[abs(s[i])].pop();
		n[abs(s[i])].pop();

		if(s[i] > 0)
		{
			ans += y - x - (get(y) - get(x));
			add(y, 1);
		}
		else
		{
			ans += x - y - (get(x) - get(y)) - 1;
			add(x, 1);
		}
		used[y] = 1;
		used[x] = 1;
	}
	return ans;
}	

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