Submission #423572

#	Time	Username	Problem	Language	Result	Execution time	Memory
423572		schse	Arranging Shoes (IOI19_shoes)	C++17	50 / 100	1108 ms	272656 KiB

shoes

#include "shoes.h"
#ifndef EVAL
#include "grader.cpp"
#endif
#include <bits/stdc++.h>
using namespace std;

long long count_swaps(std::vector<int> s)
{
	vector<int> posadd(s.size());
	vector<bool> sorted(s.size(), false);
	vector<stack<int>> pleft(s.size() + 1), plright(s.size() + 1);
	iota(posadd.begin(), posadd.end(), 0);

	long long numswaps = 0;

	for (int e, i = 0; i < s.size(); i++)
	{
		if (sorted[i])
			continue;
		for (e = i + 1; e < s.size(); e++)
		{
			if (s[i] == -s[e] && !sorted[e])
				break;
		}

		sorted[i] = sorted[e] = true;

		for (int c = i + 1; c < e; c++)
			posadd[c]++;

		numswaps += posadd[e] - posadd[i] - 1;

		if (s[i] > 0)
			numswaps++;
	}

	return numswaps;
}

Compilation message (stderr)

shoes.cpp: In function 'long long int count_swaps(std::vector<int>)':
shoes.cpp:17:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   17 |  for (int e, i = 0; i < s.size(); i++)
      |                     ~~^~~~~~~~~~
shoes.cpp:21:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   21 |   for (e = i + 1; e < s.size(); e++)
      |                   ~~^~~~~~~~~~

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