Submission #341752

#	Time	Username	Problem	Language	Result	Execution time	Memory
341752		ogibogi2004	Arranging Shoes (IOI19_shoes)	C++14	50 / 100	113 ms	44524 KiB

shoes

#include<bits/stdc++.h>
using namespace std;
#define ll long long
const ll MAXN=1e5+6;
ll fen[MAXN];
void update(ll idx,ll val)
{
	idx++;
	for(;idx<MAXN;idx+=idx&(-idx))
	{
		fen[idx]+=val;
	}
}
ll query(ll idx)
{
	idx++;
	ll ret=0;
	for(;idx>0;idx-=idx&(-idx))
	{
		ret+=fen[idx];
	}
	return ret;
}
set<int>shoes[MAXN][2];
bool vis[MAXN];
long long count_swaps(vector<int> s) {
	for(int i=0;i<s.size();i++)
	{
		if(s[i]>0)shoes[s[i]][0].insert(i);
		else shoes[-s[i]][1].insert(i);
	}
	for(int i=0;i<s.size();i++)
	{
		update(i,+1);
	}
	ll ans=0;
	for(int i=0;i<s.size();i++)
	{
		if(vis[i])continue;
		if(s[i]<0)
		{
			ll k=(*shoes[-s[i]][0].begin());
			ans+=query(k)-query(i)-1;
			update(i,+1);
			vis[k]=1;
			update(k+1,-1);
			shoes[-s[i]][0].erase(k);
			shoes[-s[i]][1].erase(i);
		}
		else
		{
			ll k=(*shoes[s[i]][1].begin());
			ans+=query(k)-query(i);
			update(i,+1);
			update(k+1,-1);
			vis[k]=1;
			shoes[s[i]][1].erase(k);
			shoes[s[i]][0].erase(i);
		}
	}
	return ans;
}

Compilation message (stderr)

shoes.cpp: In function 'long long int count_swaps(std::vector<int>)':
shoes.cpp:27:15: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   27 |  for(int i=0;i<s.size();i++)
      |              ~^~~~~~~~~
shoes.cpp:32:15: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   32 |  for(int i=0;i<s.size();i++)
      |              ~^~~~~~~~~
shoes.cpp:37:15: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   37 |  for(int i=0;i<s.size();i++)
      |              ~^~~~~~~~~

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