Submission #147308

#	Time	Username	Problem	Language	Result	Execution time	Memory
147308		joylintp	Arranging Shoes (IOI19_shoes)	C++14	100 / 100	420 ms	278392 KiB

shoes

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

using namespace std;

bool visit[400001] = {};
long long n, ret = 0, bit[400001] = {}, s[400001], ans[400001];
queue<int> Left[200001], Right[200001];

void bld(void)
{
    for (int i = 2; i <= n + 10; i++)
        bit[i] = i - max(1, i - (i & -i));
}

long long sum(int x)
{
    long long ret = 0;
    for (int i = x; i >= 1; i -= (i & -i))
        ret += bit[i];
    return ret;
}

void edt(int x, int k)
{
    for (int i = x; i <= n; i += (i & -i))
        bit[i] -= k;
}

long long count_swaps(vector<int> in)
{
    n = in.size();
    s[0] = 0;
    for (int i = 1; i <= n; i++)
    {
        s[i] = in[i - 1];
        if (s[i] < 0)
            Left[-s[i]].push(i);
        else
            Right[s[i]].push(i);
    }
    bld();

    int cnt = 0, pos, tar;
    for (int i = 1; i <= n; i++)
    {
        if (visit[i])
            continue;

        tar = -abs(s[i]);
        pos = Left[-tar].front(), Left[-tar].pop();
        ans[cnt++] = tar;
        visit[pos] = true;
        ret += sum(pos);
        edt(pos, 1);

        tar = -ans[cnt - 1];
        pos = Right[tar].front(), Right[tar].pop();
        ans[cnt++] = tar;
        visit[pos] = true;
        ret += sum(pos);
        edt(pos, 1);
    }

	return ret;
}

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