Submission #1146625

#	Time	Username	Problem	Language	Result	Execution time	Memory
1146625		mingga	Arranging Shoes (IOI19_shoes)	C++20	30 / 100	24 ms	9916 KiB

shoes

#include "bits/stdc++.h"
#include "shoes.h"

using namespace std;

#define ln "\n"
#define pb push_back
#define fi first
#define se second
#define all(x) (x).begin(), (x).end()
#define sz(x) ((int)(x).size())
#define ll long long
const int mod = 1e9 + 7;
// const int inf = 2e18;
const int N = 1e5 + 7;
struct BIT {
	vector<ll> bit;
	int n;
	BIT() {}
	BIT(int n) : n(n) {
		bit.resize(n + 1, 0);
	}
	void update(int u, ll x) {
		for(u; u <= n; u += (u & -u)) bit[u] += x;
	}
	int get(int u) {
		ll ans = 0;
		for(u; u > 0; u -= (u & -u)) ans += bit[u];
		return ans;
	}
	int get(int l, int r) {
		return get(r) - get(l - 1);
	}
};

int d[N][2];

vector<int> lef[N], rig[N];

long long count_swaps(std::vector<int> s) {
	for(int i = 0; i < sz(s); i++) {
		if(s[i] < 0) {
			lef[-s[i]].pb(i + 1);
		} else {
			rig[s[i]].pb(i + 1);
		}
	}
	int n = sz(s) / 2;
	int c = 0;
	for(int i = 1; i <= n; i++) {
		for(int j = 0; j < sz(lef[i]); j++) {
			d[++c][1] = lef[i][j];
			d[c][0] = rig[i][j];
		}
	}
	BIT bit = BIT(sz(s) + 1);
	ll ans = 0;
	for(int i = 1; i <= c; i++) {
		for(int j = 1; j >= 0; j--) {
			ll pos = i * 2 - j;
			ll sus = d[i][j] + bit.get(d[i][j] + 1, sz(s));
			bit.update(d[i][j], 1);
			ans += abs(sus - pos);
		}
	}
	return ans;
}


// signed main() {
// 	cout << count_swaps({-2, 2, 2, -2, -2, 2});
// }

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