Submission #965391

#	Time	Username	Problem	Language	Result	Execution time	Memory
965391		Syrius	Arranging Shoes (IOI19_shoes)	C++14	100 / 100	202 ms	275704 KiB

shoes

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

// #define int long long
#define ll long long
#define ff first
#define ss second
#define pint pair < int , int >
#define fast ios_base::sync_with_stdio(NULL); cin.tie(NULL)

const int inf = 1e9 + 9;
const int mxn = 2e5 + 2;
const int mod = 1e9 + 7;

ll fn[mxn];
void update(int x , int v) {
	for (; x < mxn; x += x&-x) {
		fn[x] += v;
	}
}

ll query(int l , int r) {
	ll ans = 0;
	l--;
	for (; r > 0; r -= r&-r) ans += fn[r];
	for (; l > 0; l -= l&-l) ans -= fn[l];
	return ans;
}

queue < ll > le[mxn] , ri[mxn];
bool b[mxn];

ll count_swaps(vector < int > v) {

	ll n = v.size() / 2;

	for (ll i = 0; i < 2*n; i++) {
		if (v[i] < 0) le[-v[i]].push(i);
		else ri[v[i]].push(i);
		update(i+1 , 1);
	}

	ll ans = 0;
	for (ll i = 0; i < 2*n; i++) {
		if (b[i]) continue;
		ll id;
		if (v[i] < 0) {
			id = ri[-v[i]].front();
			ans += query(i+2 , id);
			update(id+1 , -1);
		} else {
			id = le[v[i]].front();
			ans += query(i+2 , id) + 1;
			update(id+1 , -1);
		}
		ri[abs(v[i])].pop();
		le[abs(v[i])].pop();
		
		b[id] = 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