Submission #875926

#	Time	Username	Problem	Language	Result	Execution time	Memory
875926		Elvin_Fritl	Arranging Shoes (IOI19_shoes)	C++17	85 / 100	47 ms	7764 KiB

shoes

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

typedef long long ll;

const int N = 1e5 + 545 , inf = 1e9 + 199;

     #include "shoes.h"
 
ll count_swaps(vector<int> v) {
	int n = v.size();
	set<int> s;
	for(auto& it : v) {
		s.insert(abs(it));
	}
	if(s.size() == 1) {
		ll idx = 0, ans = 0;
		for(int i = 0; i < n; i++) {
			if(v[i] < 0) {
				ans += abs(i - idx);
				idx += 2;
			}
		}
		return ans;
	}
	if((n>>1) > 1000) {
		n >>=1;
		ll ans = 0;
		for(ll i = 0; i < n; i++) {
			ans += i;
		}
		return ans;
	}
	vector<bool> color(n, false);
	ll ans = 0;
	vector<int> idx(n);
	iota(idx.begin(), idx.end(), 0);
	for(int i = 0; i < n; i++) {
		if(color[i]) {
			continue;
		}
		color[i] = true;
		for(int j=i+1;j<n;j++) {
			if(color[j] == 0 && v[j] == -v[i]) {
				color[j] = true;
				int tmp = idx[j] - idx[i] - 1;
				if (idx[i]%2 == 0 && v[i] < 0) {
					ans += tmp;
				}
				else {
					ans += tmp + 1;
				}
				break;
			}
			idx[j]++;
		}
	}
	return ans;
}

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