Submission #1212453

#	Time	Username	Problem	Language	Result	Execution time	Memory
1212453		loiiii12358	Arranging Shoes (IOI19_shoes)	C++20	50 / 100	1096 ms	2632 KiB

shoes

#include "shoes.h"
#include <bits/stdc++.h>
using namespace std;

long long count_swaps(vector<int> s) {
	long long n=s.size()/2,ans=0;
	vector<int> l(n+1),r(n+1);
	pair<int,int> best;
	// set<pair<int,int>> S;
	// for(int i=0;i<2*n;i++){
	// 	S.insert({s[i],i});
	// }
	for(int i=0;i<n;i++){
		fill(l.begin(),l.end(),1e9);
		fill(r.begin(),r.end(),1e9);
		for(int j=2*i;j<2*n;j++){
			if(s[j]<0){
				l[-s[j]]=min(l[-s[j]],j-2*i);
			}else{
				r[s[j]]=min(r[s[j]],j-2*i);
			}
		}
		best={1e9,1e9};
		for(int j=1;j<=n;j++){
			if(l[j]<r[j]){
				r[j]--;
			}
			if(l[j]+r[j]<best.first){
				best={l[j]+r[j],j};
			}
		}
		for(int j=2*i;j<2*n;j++){
			if(-s[j]==best.second){
				for(int k=j-1;k>=2*i;k--){
					swap(s[k],s[k+1]);
					ans++;
				}
				break;
			}
		}
		for(int j=2*i+1;j<2*n;j++){
			if(s[j]==best.second){
				for(int k=j-1;k>=2*i+1;k--){
					swap(s[k],s[k+1]);
					ans++;
				}
				break;
			}
		}
	}
	return ans;
}

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