Submission #465351

#	Time	Username	Problem	Language	Result	Execution time	Memory
465351		dattranxxx	Arranging Shoes (IOI19_shoes)	C++14	0 / 100	0 ms	204 KiB

shoes

/*
 * Author :  shora
 */
#include "shoes.h"
#include <bits/stdc++.h>
#define print(_v) for (auto &_ : _v) {cerr << _ << ' ';} cerr << endl;
using namespace std;
using ll = long long;
const int oo = 1e9;
ll n;

namespace task_1 {
	bool check(vector<int>& a) {
		return a.size() == 2;
	}
	ll solve(vector<int>& a) {
		return a[0] > 0;
	}
}

namespace task_2 {
	bool check(vector<int>& a) {
		return a.size() <= 8;
	}
	map<vector<int>, ll> dis;
	ll solve(vector<int> a) {
		vector<int> fin(a.size());
		for (int i = 0; i < n; ++i)
			fin[2*i] = -i-1, fin[2*i+1] = i+1;
		dis[a] = 0;
		queue<vector<int>> q;
		q.push(a);
		while (!q.empty()) {
			vector<int> cur = q.front(); q.pop();
			if (cur == fin) 
				return dis[cur];
			int d = dis[cur];
			for (int i = 1; i < cur.size(); ++i) {
				swap(cur[i], cur[i-1]);
				if (!dis.count(cur)) {
					dis[cur] = d + 1;
					q.push(cur);
				}
				swap(cur[i], cur[i-1]);
			}
		}
		return dis[fin];
	}
}

namespace task_3 {
	bool check(vector<int>& a) {
		int x = a[0];
		for (int i = 1; i < a.size(); ++i)
			if (a[i] != x && a[i] != -x) return 0;
		return 1;
	}	
	ll solve(vector<int>& a) {
		ll res = 0;
		int c = 0;
		for (int i = 0; i < a.size(); ++i) {
			if (a[i] < 0) {
				res += i - c; 
				c++;
			}
		}
		return res;
	}
}

namespace task_4 {
	bool check(vector<int>& a) {
		for (int i = 0; i < n; ++i) 
			if (a[i] > 0 || a[i] != -a[i+n])
				return 0;
		return 1;
	}
	ll solve(vector<int>& a) {
		return n * (n-1) / 2;
	}
}

long long count_swaps(std::vector<int> a) {
	n = a.size() / 2;
	if (task_1::check(a)) return task_1::check(a);
	if (task_2::check(a)) return task_2::solve(a);
	if (task_3::check(a)) return task_3::solve(a);
	if (task_4::check(a)) return task_4::solve(a);
	return -1;
}

Compilation message (stderr)

shoes.cpp: In function 'll task_2::solve(std::vector<int>)':
shoes.cpp:38:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   38 |    for (int i = 1; i < cur.size(); ++i) {
      |                    ~~^~~~~~~~~~~~
shoes.cpp: In function 'bool task_3::check(std::vector<int>&)':
shoes.cpp:54:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   54 |   for (int i = 1; i < a.size(); ++i)
      |                   ~~^~~~~~~~~~
shoes.cpp: In function 'll task_3::solve(std::vector<int>&)':
shoes.cpp:61:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   61 |   for (int i = 0; i < a.size(); ++i) {
      |                   ~~^~~~~~~~~~

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