Submission #1033877

#	Time	Username	Problem	Language	Result	Execution time	Memory
1033877		AmirAli_H1	Arranging Shoes (IOI19_shoes)	C++17	100 / 100	63 ms	22104 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 = 2e5 + 7;

int n, sz;
vector<int> ls1[maxn], ls2[maxn];
pii val[maxn]; int arr[maxn];
ll t[maxn];

bool cmp(pii a, pii b) {
	return (min(a.F, a.S) < min(b.F, b.S));
}

void addx(int i, ll x) {
	for (++i; i <= 2 * n; 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 get_inv() {
	ll res = 0;
	for (int i = 2 * n - 1; i >= 0; i--) {
		res += getx(arr[i]);
		addx(arr[i], 1);
	}
	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) ls1[j].pb(i);
		else ls2[j].pb(i);
	}
	int sz = 0;
	for (int i = 0; i < n; i++) {
		for (int j = 0; j < len(ls1[i]); j++) {
			val[sz] = Mp(ls1[i][j], ls2[i][j]);
			sz++;
		}
	}
	sort(val, val + n, cmp);
	
	for (int i = 0; i < 2 * n; i += 2) {
		arr[i] = val[i / 2].F; arr[i + 1] = val[i / 2].S;
	}
	return get_inv();
}

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