Submission #799486

#	Time	Username	Problem	Language	Result	Execution time	Memory
799486		ZeroCool	Arranging Shoes (IOI19_shoes)	C++14	65 / 100	266 ms	26176 KiB

shoes

#include "shoes.h"
#include <bits/stdc++.h>
#define ll long long
 
using namespace std;
 
const int mxn = 200020;
 
struct FenwickTree{
	ll bit[mxn];
 
	FenwickTree(){
		memset(bit,0,sizeof(bit));	
	}
 
	void add(int pos){
		for(int i = pos;i<mxn;i += i&(-i))bit[i]++;
	}
	ll query(int pos){
		ll ans = 0;
		for(int i = pos;i;i-=i&(-i))ans+=bit[i];
		return ans;
 
	}
};
 
ll count_swaps(vector<int> A) {
	int n = A.size();
 
	map<int,vector<int> > ind;
	for(int i = 0;i<n;i++){
		ind[A[i]].push_back(i);
	}
	for(auto &i : ind)reverse(i.second.begin(),i.second.end());//Gi reversame vektorite za da imame pobrzi oparacii so pop i push back
	int order[n];
	for(int i = 0;i<n;i++)order[i] = 0;

 
	for(int i = 0;i<n;i++){
		if(order[i])continue;
		if(A[i] < 0){
			ind[A[i]].pop_back();
			order[i] = i * 2 + 1;
			order[ind[-A[i]].back()] = i * 2 + 2;
			ind[-A[i]].pop_back();
		}else{
			ind[A[i]].pop_back();
            order[i]=i * 2 + 2;
            order[ind[-A[i]].back()]=i * 2 + 1;
            ind[-A[i]].pop_back();
		}
	}
	ll ans = 0;
	FenwickTree fwt;
 
	for(int i = n-1;i>=0;i--){
		ans += fwt.query(order[i] -1 );
		fwt.add(order[i]);
	}
 
	return ans;
}

• Subtask 1: 10 / 10
• Subtask 2: 20 / 20
• Subtask 3: 0 / 20
• Subtask 4: 15 / 15
• Subtask 5: 20 / 20
• Subtask 6: 0 / 15