Submission #268130

#	Time	Username	Problem	Language	Result	Execution time	Memory
268130		shinjan	Arranging Shoes (IOI19_shoes)	C++14	100 / 100	204 ms	138744 KiB

shoes

#include <iostream>
#include <bits/stdc++.h>
#include "shoes.h"
#define maxN 200005
using namespace std;
int fen[maxN];
void add(int ind,int n)
{
    for(int i=ind;i<=n;i+=(i&(-i)))
    {
        fen[i]++;
    }
}
void brisi(int ind,int n)
{
    for(int i=ind;i<=n;i+=(i&(-i)))
    {
        fen[i]--;
    }
}
long long sum(int ind)
{
    long long ans=0;
    for(int i=ind;i>=1;i-=(i&(-i)))
    {
        ans+=fen[i];
    }
    return ans;
}
long long count_swaps(vector <int> s)
{
    int n=s.size();
    long long ans=0;
    queue<int> neg[n/2+1];
    queue<int> poz[n/2+1];
    for(int i=0;i<s.size();i++)
    {
        if(s[i]>0)
        {
            if(neg[s[i]].size()!=0)
            {
                int pos=neg[s[i]].front();
                ans-=(sum(i)-sum(pos+1));
                brisi(pos+1,n);
                ans+=(i-pos-1);
                neg[s[i]].pop();
            }
            else{
                poz[s[i]].push(i);
                add(i+1,n);
            }
        }
        if(s[i]<0)
        {
            int x=abs(s[i]);
            if(poz[x].size()!=0)
            {
                int pos=poz[x].front();
                ans-=(sum(i)-sum(pos+1));
                brisi(pos+1,n);
                ans+=(i-pos);
                poz[x].pop();
            }
            else{
                neg[x].push(i);
                add(i+1,n);
            }
        }
    }
    return ans;
}

Compilation message (stderr)

shoes.cpp: In function 'long long int count_swaps(std::vector<int>)':
shoes.cpp:36:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   36 |     for(int 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