Submission #584418

#	Time	Username	Problem	Language	Result	Execution time	Memory
584418		KrisjanisP	Arranging Shoes (IOI19_shoes)	C++14	100 / 100	518 ms	148020 KiB

shoes

#include "shoes.h"
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<ll,ll> pii;

struct FenwickTree {
    vector<int> bit;  // binary indexed tree
    int n;

    FenwickTree(int n) {
        this->n = n;
        bit.assign(n, 0);
    }
    int sum(int r) {
        int ret = 0;
        for (; r >= 0; r = (r & (r + 1)) - 1)
            ret += bit[r];
        return ret;
    }
    int sum(int l, int r) {
        return sum(r) - sum(l - 1);
    }
    void add(int idx, int delta) {
        for (; idx < n; idx = idx | (idx + 1))
            bit[idx] += delta;
    }
};

ll count_swaps(vector<int> s) {
	ll n = s.size();
	map<ll,queue<ll>> m;
	for(ll i=0;i<n;i++)
		m[s[i]].push(i);
	
	FenwickTree ft(n+100);
	set<ll> erased;
	ll res = 0;
	for(ll i=0;i<n;i++)
	{
		if(ft.sum(i,i)==1) continue;
		
		m[s[i]].pop();

		ll j = m[-s[i]].front();
		m[-s[i]].pop();
		
		res += j-i-1;
		if(s[i]>0) res++;
		res -= ft.sum(i+1,j);
		ft.add(i,1);
		ft.add(j,1);
	}
	return res;
}

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