Submission #1224931

#	Time	Username	Problem	Language	Result	Execution time	Memory
1224931		AmirAli_H1	Arranging Shoes (IOI19_shoes)	C++17	100 / 100	66 ms	57532 KiB

shoes

// In the name of Allah

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

typedef		long long int			ll;
typedef		long double				ld;
typedef		pair<int, int>			pii;
typedef		pair<ll, ll>			pll;
typedef		complex<ld>				cld;

#define		all(x)					(x).begin(),(x).end()
#define		len(x)					((ll) (x).size())
#define		F						first
#define		S						second
#define		pb						push_back
#define		sep						' '
#define		endl					'\n'
#define		Mp						make_pair
#define		kill(x)					cout << x << '\n', exit(0)
#define		set_dec(x)				cout << fixed << setprecision(x);
#define		file_io(x,y)			freopen(x, "r", stdin); freopen(y, "w", stdout);
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

const int maxn = 1e6 + 4;

int n; vector<pii> lsx;
vector<int> ls0[maxn], ls1[maxn];
ll t[maxn];

void addx(int i, ll x) {
	for (++i; i < maxn; i += (i & -i)) t[i] += x;
}

ll getx(int i) {
	ll res = 0;
	for (++i; i > 0; i -= (i & -i)) res += t[i];
	return res;
}

ll count_swaps(vector<int> s) {
	n = len(s) / 2;
	for (int i = 0; i < (2 * n); i++) {
		int j = abs(s[i]) - 1;
		if (s[i] < 0) ls0[j].pb(i);
		else ls1[j].pb(i);
	}
	ll ans = 0;
	for (int i = 0; i < n; i++) {
		for (int j = 0; j < len(ls0[i]); j++) {
			int lx = ls0[i][j], rx = ls1[i][j];
			if (lx > rx) {
				swap(lx, rx); ans++;
			}
			lsx.pb(Mp(lx, rx));
		}
	}
	sort(all(lsx)); reverse(all(lsx));
	for (auto f : lsx) {
		int lx = f.F, rx = f.S;
		ans += getx(rx - 1) - getx(lx);
		addx(lx, 1); addx(rx, 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