Submission #297358

#	Time	Username	Problem	Language	Result	Execution time	Memory
297358		amoo_safar	Arranging Shoes (IOI19_shoes)	C++17	100 / 100	112 ms	25080 KiB

shoes

#include "shoes.h"

#include <bits/stdc++.h>

#define pb push_back
#define F first
#define S second
#define all(x) x.begin(), x.end();

using namespace std;

typedef long long ll;

const int N = 2e5 + 10;
vector<int> V[N];
vector<int> pos[N], neg[N];
int v[N];

int fen[N];
void Add(int idx){
	idx ++;
	for(; idx < N; idx += (idx & -idx))
		fen[idx] ++;
}
int Get(int idx){
	idx ++;
	int res = 0;
	for(; idx; idx -= idx & (-idx))
		res += fen[idx];
	return res;
}

ll count_swaps(vector<int> s) {
	int n = s.size() >> 1;
	for(int i = 0; i < n + n; i++){
		if(s[i] > 0)
			pos[abs(s[i])].pb(i);
		else
			neg[abs(s[i])].pb(i);
	}
	ll res = 0;
	for(int i = 1; i <= n; i++){
		for(int j = 0; j < (int) pos[i].size(); j++){
			v[pos[i][j]] = v[neg[i][j]] = min(pos[i][j], neg[i][j]);
			if(v[pos[i][j]] == pos[i][j])
				res ++;
		}
	}
	for(int i = n + n - 1; i >= 0; i--){
		res += Get(v[i] - 1);
		Add(v[i]);
	}
	return res;
}

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