Submission #240870

#	Time	Username	Problem	Language	Result	Execution time	Memory
240870		RayaBurong25_1	Arranging Shoes (IOI19_shoes)	C++17	100 / 100	806 ms	147128 KiB

shoes

#include "shoes.h"
#include <map>
#include <vector>
#include <algorithm>
#include <queue>
#include <cassert>

int abs(int a)
{
	return (a < 0)?-a:a;
}

int ismoved[200005] = {0};
int query(int p)
{
	p++;
	int r = 0;
	for (; p > 0; p -= p&-p)
		r += ismoved[p];
	return r;
}
void update(int p)
{
	p++;
	for (; p < 200005; p += p&-p)
		ismoved[p]++;
}

long long count_swaps(std::vector<int> s) {
	int i, sz, norp;
	long long cnt = 0;
	std::map<int, std::queue<int> > pos[2];
	for (i = 0; i < s.size(); i++)
	{
		sz = abs(s[i]);
		norp = (s[i] > 0);
		if (pos[norp].find(sz) == pos[norp].end())
			pos[norp][sz] = std::queue<int>();
		pos[norp][sz].push(i);
	}
	std::vector<int> moved;
	int nxt;
	for (i = 0; i < s.size(); i++)
	{
		sz = abs(s[i]);
		norp = (s[i] > 0);
		if (i > 0 && query(i) - query(i-1))
			continue;
		// printf("%d ", sz);
		if (pos[!norp][sz].size() == 0)
			continue;
		nxt = pos[!norp][sz].front();
		// printf("%d ", pos[sz][nxt]);
		cnt += (nxt - i - 1) - (query(nxt) - query(i));
		// printf("%d ", (s[i] > 0));
		cnt += (s[i] > 0);
		update(nxt);
		pos[!norp][sz].pop();
		pos[norp][sz].pop();
		// printf("%lld\n", cnt);
	}
	return cnt;
}

Compilation message (stderr)

shoes.cpp: In function 'long long int count_swaps(std::vector<int>)':
shoes.cpp:33:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for (i = 0; i < s.size(); i++)
              ~~^~~~~~~~~~
shoes.cpp:43:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for (i = 0; i < s.size(); i++)
              ~~^~~~~~~~~~

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