Submission #283545

#	Time	Username	Problem	Language	Result	Execution time	Memory
283545		test2	Arranging Shoes (IOI19_shoes)	C++14	10 / 100	1092 ms	23276 KiB

shoes

#include<bits/stdc++.h>
#include "shoes.h"

#define I inline void 


using namespace std ; 

using ll = long long ; 
using ld = long double ; 

const int N = 3000 + 7 , mod = 1e9 + 7 ;

// How interesting!

int n; 


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

	map<int,vector<int> > mp ; 

	ll ret = 1e9 ; 

	vector<pair<int,int>> v ; 

	int pos = 0 ; 
	for(auto u : s){
		if(mp[-u].size()){
			v.push_back({mp[-u].back() , pos}) ; 
			mp[-u].pop_back() ; 
		}
		else{
			mp[u].push_back(pos) ; 
		}

		pos ++ ; 
	}
	int n = (int) s.size() ; 
	vector<int> per ; 
	for(int i = 0 ;i < n ;i ++){
		per.push_back(i) ; 
	}

	for(auto u : v){
		//cout<< u.first <<" " << u.second <<"..\n" ;
	}

	do{
		bool bad = 0 ;
		ll ret1 = 0 ; 
		for(int i = 1 ;i < n;i+=2){
			int x = s[per[i-1]] , y = s[per[i]] ;
			if(!(x == -y && x < y)){
				bad = 1; 
				break ; 
			}
			ret1+= abs(i - per[i]) ; 
			ret1+= abs((i-1) - per[i-1]) ; 
		}

		if(!bad){
			ret = min(ret , ret1 / 2) ; 
		}
	}
	while(next_permutation(per.begin() , per.end())) ; 
	return ret;
}

Compilation message (stderr)

shoes.cpp: In function 'long long int count_swaps(std::vector<int>)':
shoes.cpp:45:11: warning: variable 'u' set but not used [-Wunused-but-set-variable]
   45 |  for(auto u : v){
      |           ^

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