Submission #583889

#	Time	Username	Problem	Language	Result	Execution time	Memory
583889		8e7	Arranging Shoes (IOI19_shoes)	C++17	100 / 100	81 ms	19568 KiB

shoes

//Challenge: Accepted
#include <bits/stdc++.h>
#include "shoes.h"
#pragma GCC optimize("Ofast")
using namespace std;
#ifdef zisk
void debug(){cout << endl;}
template<class T, class ... U> void debug(T a, U ... b){cout << a << " ", debug(b...);}
template<class T> void pary(T l, T r) {
	while (l != r) cout << *l << " ", l++;
	cout << endl;
}
#else
#define debug(...) 0
#define pary(...) 0
#endif
#define ll long long
#define maxn 200005
#define mod 1000000007
#define pii pair<int, int>
#define ff first
#define ss second
#define io ios_base::sync_with_stdio(0);cin.tie(0);
struct BIT{
	int bit[maxn];
	void modify(int ind, int val) {
		ind++;
		for (;ind < maxn;ind += ind & (-ind)) bit[ind] += val;
	}
	int query(int ind) {
		ind++;
		int ret = 0;
		for (;ind > 0;ind -= ind & (-ind)) ret += bit[ind];
		return ret;
	}
}bit;
vector<int> lef[maxn], rig[maxn];
long long count_swaps(std::vector<int> s) {
	int n = s.size();	
	vector<bool> p(n, 1);
	for (int i = 0;i < n;i++) bit.modify(i, 1);	
	for (int i = 0;i < n;i++) {
		if (s[i] < 0) lef[-s[i]].push_back(i);
		else rig[s[i]].push_back(i);
	}
	for (int i = 1;i <= n;i++) {
		reverse(lef[i].begin(), lef[i].end());
		reverse(rig[i].begin(), rig[i].end());
	}
	ll ret = 0;
	for (int i = 0;i < n;i++) {
		if (!p[i]) continue;
		if (s[i] < 0) {
			int x = rig[-s[i]].back();
			lef[-s[i]].pop_back();
			rig[-s[i]].pop_back();
			bit.modify(i, -1);		
			bit.modify(x, -1);		
			p[i] = p[x] = 0;
			ret += bit.query(x);
		} else {
			int x = lef[s[i]].back();
			lef[s[i]].pop_back();
			rig[s[i]].pop_back();
			bit.modify(i, -1);		
			bit.modify(x, -1);		
			p[i] = p[x] = 0;
			ret += bit.query(x) + 1;
		}
	}
	return ret;
}
/*

*/

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