Submission #211173

#	Time	Username	Problem	Language	Result	Execution time	Memory
211173		thomaswang	Arranging Shoes (IOI19_shoes)	C++14	10 / 100	100 ms	135032 KiB

shoes

#include <bits/stdc++.h>
#define ericxiao cin.tie(0); ios_base::sync_with_stdio(false);
#define endl '\n'
// #define int long long
using namespace std;
typedef pair<int,int> pii;
const int maxn=1e5+10;
deque<int> posl[maxn],posr[maxn];
struct BIT{
	int v[maxn],n;
	int lb(int x){return x&(-x);}
	void init(int x){n=x; for(int i=1;i<=n;i++) v[i]=lb(i);}
	void modify(int x,int k){while(x<=n) v[x]+=k,x+=lb(x);}
	int query(int x){int t=0; while(x>0) t+=v[x],x-=lb(x); return t;}
	int get(int l,int r){return query(r+1)-query(l);}
	void del(int x){modify(x+1,-1);}
	void print(){for(int i=0;i<n;i++) cout<<get(i,i)<<' '; cout<<endl;}
} tree;
int count_swaps(vector<int> v){
	int n=v.size(),ans=0; tree.init(n);
	for(int i=0;i<n;i++){
		if(v[i]>0) posr[v[i]].push_back(i);
		else posl[-v[i]].push_back(i);
	}
	// tree.print();
	for(int i=0;i<n/2;i++){
		if(v[i]>0)
			ans+=tree.get(0,posl[v[i]].front())-1;
		else
			ans+=tree.get(1,posr[-v[i]].front())-1;
		tree.del(posl[abs(v[i])].front()); tree.del(posr[abs(v[i])].front());
		posl[abs(v[i])].pop_front(); posr[abs(v[i])].pop_front();
		// tree.print(); cout<<"ans: "<<ans<<endl;
	}
	return ans;
}
// signed main(){
// 	int n; cin>>n;
// 	vector<int> v(n);
// 	for(int i=0;i<n;i++) cin>>v[i];
// 	cout<<count_swaps(v)<<endl;
// 	return 0;
// }

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