Submission #870749

#	Time	Username	Problem	Language	Result	Execution time	Memory
870749		Eliorita	Arranging Shoes (IOI19_shoes)	C++14	100 / 100	114 ms	142808 KiB

shoes

#include "shoes.h"
#include <algorithm>
#include <iostream>
#include <vector>
#include <queue>
using namespace std;
const long long N=200010;
typedef pair<long long,long long> ii;
typedef pair<double,double> dd;
long long n,c[N],temp[N],pr[N],cnt;
queue<int> nxt[100001][2];
long long merge(int l,int mid,int r)
{
    long long cnt=0;
    int i=l,j=mid,k=l;
    while((i<=mid-1)&&(j<=r))
    {
        if(c[i]<=c[j]) temp[k++]=c[i++];
        else
        {
            temp[k++]=c[j++];
            cnt+=1ll*(mid-i);
        }
    }
    while(i<=mid-1) temp[k++]=c[i++];
    while(j<=r) temp[k++]=c[j++];
    for(int i=l;i<=r;i++) c[i]=temp[i];
    return cnt;
}
long long mergesort(int l,int r)
{
    long long cnt=0;
    if(l<r)
    {
        long long mid=(l+r)/2;
        cnt+=mergesort(l,mid);
        cnt+=mergesort(mid+1,r);
        cnt+=merge(l,mid+1,r);
    }
    return cnt;
}
long long count_swaps(std::vector<int> s) {
    n=s.size()/2;
    for(int i=2*n-1;i>=0;i--)
    {
        if(s[i]<0)
        {
            if(nxt[-s[i]][1].empty()) nxt[-s[i]][0].push(i);
            else
            {
                pr[i]=nxt[-s[i]][1].front();
                nxt[-s[i]][1].pop();
            }
        }
        else
        {
            if(nxt[s[i]][0].empty()) nxt[s[i]][1].push(i);
            else
            {
                pr[i]=nxt[s[i]][0].front();
                nxt[s[i]][0].pop();
            }
        }
    }
    for(int i=0;i<2*n;i++)
    {
        if(pr[i]!=0)
        {
            c[i]=++cnt;
            c[pr[i]]=++cnt;
            if(s[i]>0) swap(c[i],c[pr[i]]);
        }
    }
    return mergesort(0,2*n-1);
}

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