Submission #719508

#	Time	Username	Problem	Language	Result	Execution time	Memory
719508		baojiaopisu	Arranging Shoes (IOI19_shoes)	C++14	100 / 100	139 ms	34724 KiB

shoes

#include<bits/stdc++.h>

using namespace std;

using ll = long long;
using ld = long double;
using ull = unsigned long long;

using pii = pair<int, int>;
using pll = pair<ll, ll>;
using pld = pair<ld, ld>;

#define fi first
#define se second
#define left BAO
#define right ANH
#define pb push_back
#define pf push_front
#define mp make_pair
#define ins insert
#define btpc __builtin_popcount
#define btclz __builtin_clz

#define sz(x) (int)(x.size());
#define all(x) x.begin(), x.end()
#define debug(...) " [" << #__VA_ARGS__ ": " << (__VA_ARGS__) << "] "

mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

int d4x[4] = {1, 0, -1, 0}; int d4y[4] = {0, 1, 0, -1};
int d8x[8] = {0, 1, 1, 1, 0, -1, -1, -1};
int d8y[8] = {1, 1, 0, -1, -1, -1, 0, 1};

template<class X, class Y>
    bool minimize(X &x, const Y &y) {
        if (x > y)
        {
            x = y;
            return true;
        }
        return false;
    }
template<class X, class Y>
    bool maximize(X &x, const Y &y) {
        if (x < y)
        {
            x = y;
            return true;
        }
        return false;
    }

const int MOD = 1e9 + 7; //998244353

template<class X, class Y>
	void add(X &x, const Y &y) {
		x = (x + y);
		if(x >= MOD) x -= MOD;
	}

template<class X, class Y> 
	void sub(X &x, const Y &y) {
		x = (x - y);
		if(x < 0) x += MOD;
	}

/* Author : Le Ngoc Bao Anh, 12A5, LQD High School for Gifted Student*/

const ll INF = 1e9;
const int N = 2e5 + 10;

template <class T> struct FenwickTree {
	int n;
	vector<T> bit;

	FenwickTree(int _n = 0) {
		n = _n;
		bit.resize(n + 5);
		for(int i = 1; i <= n; i++) bit[i] = 0;
	}

	void update(int pos, T x) {
		for(int i = pos; i <= n; i += i & (-i)) bit[i] += x;
	}

	T get(int pos) {
		T ans = 0;
		for(int i = pos; i > 0; i -= i & (-i)) ans += bit[i];
		return ans;
	}
};

set<int> left[N], right[N];
int a[N], b[N];
bool ok[N];

ll count_swaps(vector<int> A) {
	int n = A.size();
	vector<int> val;
	for(int i = 1; i <= n; i++) a[i] = A[i - 1];
	for(int i = 1; i <= n; i++) {
		if(a[i] < 0) {
			b[i] = -1;
		} else b[i] = 1;
		a[i] = fabs(a[i]);
		val.pb(a[i]);
	}

	sort(all(val));
	val.resize(unique(all(val)) - val.begin());
	for(int i = 1; i <= n; i++) {
		a[i] = lower_bound(all(val), a[i]) - val.begin() + 1;
		if(b[i] < 0) left[a[i]].ins(i);
		else right[a[i]].ins(i);
	}
	FenwickTree<int> BIT = FenwickTree<int>(n);

	ll ans = 0;
	for(int i = 1; i <= n; i++) {
		if(ok[i]) continue;
		if(b[i] < 0) {
			auto iter = right[a[i]].begin();
			int pos = (*iter);
			right[a[i]].erase(iter);
			left[a[i]].erase(i);
			ok[pos] = true;
			int p = BIT.get(pos);
			BIT.update(pos, -1);
			pos += p;
			ans += pos - 2;
		} else {
			auto iter = left[a[i]].begin();
			int pos = (*iter);
			left[a[i]].erase(iter);
			right[a[i]].erase(i);
			ok[pos] = true;
			int p = BIT.get(pos);
			BIT.update(pos, -1);
			pos += p;
			ans += pos - 1;
		}
		BIT.update(i, -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