Submission #554447

#	Time	Username	Problem	Language	Result	Execution time	Memory
554447		n0sk1ll	Arranging Shoes (IOI19_shoes)	C++14	100 / 100	377 ms	28108 KiB

shoes

#include "shoes.h"
#include <bits/stdc++.h>

using namespace std;
long long int typedef li;

int n;
int fwt[200005];

void add(int i)
{
    for (;i<=2*n;i+=(i&-i)) fwt[i]++;
}
int pre(int i)
{
    li ret=0;
    for (;i;i-=(i&-i)) ret+=fwt[i];
    return ret;
}

int gde[200005];
li invcount(int n)
{
    li ans=0;
    //for (int i=0;i<2*n;i++) cout<<gde[i]<<" "; cout<<endl;
    for (int i=0;i<2*n;i++)
    {
        ans+=i-pre(gde[i]);
        //cout<<i<<": "<<pre(gde[i])<<endl;
        //for (int i=1;i<=2*n;i++) cout<<fwt[i]<<","; cout<<endl<<endl;
        add(gde[i]);
    }

    return ans;
}

int cntpoz[100005];
int cntneg[100005];

li count_swaps(vector<int> s)
{
	n=s.size()/2;
	vector<int> pom; map<int,vector<int>> poz;

	for (int i=0;i<2*n;i++)
    {
        if (s[i]>0)
        {
            if (cntpoz[s[i]]) cntpoz[s[i]]--;
            else cntneg[s[i]]++,pom.push_back(-s[i]),pom.push_back(s[i]);
        }
        else
        {
            if (cntneg[-s[i]]) cntneg[-s[i]]--;
            else cntpoz[-s[i]]++,pom.push_back(s[i]),pom.push_back(-s[i]);
        }
    }

	for (int i=0;i<2*n;i++) poz[s[i]].push_back(i);
	for (int i=2*n-1;i>=0;i--) gde[i]=poz[pom[i]].back()+1,poz[pom[i]].pop_back();

    return invcount(n);
}

/*

2
1 2 -1 -2

*/

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