Submission #1230455

#	Time	Username	Problem	Language	Result	Execution time	Memory
1230455		neisenn	Arranging Shoes (IOI19_shoes)	C++20	0 / 100	1096 ms	320 KiB

shoes

#include "shoes.h"
#include <iostream>
#include <vector>
#include <map>
#include <queue>
using namespace std;

struct BIT {
	vector<int> f; int n;
	void init(int _n){
		f.resize(2*_n+2, 0);
		n = _n;
	}
	void add(int x, int v){
		for (int i = x; i <= n; i += i & -i){
			f[i] += v;
		}
	}
	int query(int l){
		int ret = 0;
		for (int i = l; i > 0; i -= i & -i){
			ret += f[i];
		}
		return ret;
	}
	int query(int l, int r){
		return query(r)-query(l-1);
	}
}; 

long long count_swaps(std::vector<int> s){
	int n = s.size()/2;
	BIT bit;
	bit.init(n);
	map<int, priority_queue<int, vector<int>, greater<int>>> l, r;
	for (int i = 0; i < 2*n; i++){
		if (s[i] < 0){
			l[abs(s[i])].push(i);
		}
		else {
			r[s[i]].push(i);
		}
	}
	vector<bool> vis(2*n+1, 0);
	long long ans = 0;
	for (int i = 0; i < 2*n; i++){
		if (!vis[i]){
			int id;
			if (s[i] < 0) id = r[abs(s[i])].top();
			else id = l[s[i]].top();
			l[abs(s[i])].pop();
			r[abs(s[i])].pop();
			ans += abs(id-i)-1;
			ans -= bit.query(i+1, id);
			bit.add(id, 1);
			vis[i] = 1;
		}
	}
	return ans;
}

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