Submission #1149727

#	Time	Username	Problem	Language	Result	Execution time	Memory
1149727		kvintsekstakord	Arranging Shoes (IOI19_shoes)	C++20	100 / 100	348 ms	39556 KiB

shoes

#include "shoes.h"
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>

using namespace std;

using namespace __gnu_pbds;

using iset = tree<int, null_type, less<int>, rb_tree_tag, tree_order_statistics_node_update>;


long long count_swaps(std::vector<int> s) {

	int n = s.size();
	iset arr;
	map<int, set<int>> pos;
	for(int i = 0; i < n; i++){
		arr.insert(i);
		pos[s[i]].insert(i);
	}
	long long ans = 0;
	while(!arr.empty()){
		int beg = s[*arr.begin()];
		int pairpos = *pos[-beg].begin();


		int order = arr.order_of_key(pairpos);
		if(beg>0){
			ans+=order;
		}else ans+=order-1;

		pos[-beg].erase(pairpos);
		pos[beg].erase(*arr.begin());
		arr.erase(*arr.begin());
		arr.erase(pairpos);

	}

	return ans;
}

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