Submission #1030494

#	Time	Username	Problem	Language	Result	Execution time	Memory
1030494		ender	Arranging Shoes (IOI19_shoes)	C++17	65 / 100	40 ms	4404 KiB

shoes

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

using namespace std;

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

	if(s.size() > 16){

		long long ans = 0;
	int cl = 0, cr = 0;
	priority_queue<int, vector<int>, greater<int>> l, r;
 
	for(int i = 0; i < s.size(); ++i){
 
		if(s[i] < 0) l.push(i);
		else r.push(i);
 
	}
 
	for(int i = 0; i < s.size(); ++i){
 
		if(i%2 == 0){
 
			if(s[i] > 0){
				
				ans += l.top() - i;
				swap(s[i], s[l.top()]);
				r.pop();
				r.push(l.top());
			} 
 
			l.pop();
 
		}else {
 
			if(s[i] < 0){
 
				ans += r.top() - i;
				swap(s[i], s[r.top()]);	
				l.pop();
				l.push(r.top());
			} 
			
			r.pop();
 
		}
 
	}

	return ans;


	}

	int n = s.size()/2;
	vector<int> p;
	for(const auto &i : s) if(i > 0) p.push_back(i);
	//for(int i = 1; i <= n; ++i) p.push_back(i);
	sort(p.begin(), p.end());
	long long ans = 1e18;

	do{
		long long cnt = 0;
		vector<int> curr; // same size as s
		vector<int> current_s(s.begin(), s.end());
		for(int i = 0; i < n; ++i){
			curr.push_back(-p[i]);
			curr.push_back(p[i]);

		}

		for(int i = 0; i < s.size(); ++i){

		if(i%2 == 0){ // debe ser zapato izquierdo

			if(current_s[i] == curr[i]) continue;

			for(int j = i+1; j < s.size(); ++j){

				if(current_s[j] == curr[i]){

					for(int k = j; k > i; --k){

						swap(current_s[k], current_s[k-1]);
						cnt++;

					}

					break;

				}

			}

		}else { // debe ser zapato derecho

			if(current_s[i] == current_s[i-1] * -1) continue;

			int target = current_s[i-1] * -1;

			for(int j = i+1; j < s.size(); ++j){

				if(current_s[j] == target){

					for(int k = j; k > i; --k){

						swap(current_s[k], current_s[k-1]);
						cnt++;

					}

					break;

				}

			}


		}

	}

	ans = min(cnt, ans);

	} while (next_permutation(p.begin(), p.end()));

	return ans;
}

Compilation message (stderr)

shoes.cpp: In function 'long long int count_swaps(std::vector<int>)':
shoes.cpp:14:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   14 |  for(int i = 0; i < s.size(); ++i){
      |                 ~~^~~~~~~~~~
shoes.cpp:21:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   21 |  for(int i = 0; i < s.size(); ++i){
      |                 ~~^~~~~~~~~~
shoes.cpp:11:6: warning: unused variable 'cl' [-Wunused-variable]
   11 |  int cl = 0, cr = 0;
      |      ^~
shoes.cpp:11:14: warning: unused variable 'cr' [-Wunused-variable]
   11 |  int cl = 0, cr = 0;
      |              ^~
shoes.cpp:73:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   73 |   for(int i = 0; i < s.size(); ++i){
      |                  ~~^~~~~~~~~~
shoes.cpp:79:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   79 |    for(int j = i+1; j < s.size(); ++j){
      |                     ~~^~~~~~~~~~
shoes.cpp:102:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  102 |    for(int j = i+1; j < s.size(); ++j){
      |                     ~~^~~~~~~~~~

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