Submission #433194

#	Time	Username	Problem	Language	Result	Execution time	Memory
433194		kostia244	Arranging Shoes (IOI19_shoes)	C++17	10 / 100	1 ms	204 KiB

shoes

#include "shoes.h"
#include<bits/stdc++.h>
using namespace std;
using ll = long long;
#define all(x) begin(x), end(x)
long long count_swaps(std::vector<int> s) {
	int n = s.size()/2;
	ll res = 0;
	for(auto &i : s) i = 2*abs(i) + (i>0);
	vector<array<int, 2>> b;
	for(int i = 0; i < 2*n; i++) 
		b.push_back({s[i], i+1});
	sort(all(b));
	vector<ll> fen(2*n+1);
	auto add = [&](int x) {
		for(; x <= 2*n; x += x&-x) fen[x]++;
	};
	auto get = [&](int x) {
		int res = 0;
		add(x);
		for(; x; x -= x&-x)
			res += fen[x];
		return res;
	};
	int cur = 0;
	for(auto [_, i] : b) {
		res += ++cur - get(i);
	}
	return res;
}

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