Submission #547316

#	Time	Username	Problem	Language	Result	Execution time	Memory
547316		Sergio_2357	Arranging Shoes (IOI19_shoes)	C++17	30 / 100	65 ms	29372 KiB

shoes

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

using namespace std;

typedef vector<int> vi;
typedef vector<vi> vii;

const int sizea = 100000;
const int sqrts = 316;
const int sqrtn = (sizea / sqrts + 1);

vi norms(sizea);
vi sqrtarr(sqrtn);

void update(int b, int e, int v)
{
    int idx = sizea;
    for (int i = b; i < e; i++) {
        norms[i] += v;
        if (i % sqrts == sqrts - 1) {
            idx = i + sqrts;
            break;
        }
    }
    for (int i = idx; i < e; i += sqrts) {
        sqrtarr[i / sqrts] += v;
        idx = i + 1;
    }
    for (int i = idx; i < e; i++) {
        norms[i] += v;
    }
}

int get(int i)
{
    return norms[i] + sqrtarr[i / sqrts];
}

int gidx(int v, int n)
{
    return v + (n / 2);
}

long long count_swaps(vi s)
{
    int n = s.size();
    iota(norms.begin(), norms.end(), 0);
    vi used(n, 0);
    vii last(n + 2);
    for (int i = 0; i < n; i++)
        last[gidx(s[i], n)].push_back(i);
    for (int i = 0; i < n + 2; i++)
        reverse(last[i].begin(), last[i].end());
    long long c = 0;
    for (int i = 0; i < n; i++) {
        if (used[i])
            continue;
        //cout << i << endl;
        int r = gidx(-s[i], n);
        int nxt = *prev(last[r].end());
        last[gidx(s[i], n)].pop_back();
        last[r].pop_back();
        used[i] = 1;
        used[nxt] = 1;
        //cout << i << ' ' << nxt << endl;
        //cout << get(i) << ' ' << get(nxt) << endl;
        int d = get(nxt) - get(i);
        d--;
        if (s[i] > 0)
            d++;
        //cout << d << endl;
        c += d;
        update(i + 1, nxt, 1);
    }
    return c;
}

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