Submission #376641

#	Time	Username	Problem	Language	Result	Execution time	Memory
376641		beingsebi	Arranging Shoes (IOI19_shoes)	C++17	100 / 100	335 ms	31224 KiB

shoes

#include <bits/stdc++.h>
typedef long long ll;
using namespace std;
ll solve(vector<int> &ax)
{
    vector<int> aib(ax.size() + 12);
    auto qr = [&aib](int poz) {
        ll rez = 0;
        while (poz > 0)
            rez += aib[poz], poz -= poz & -poz;
        return rez;
    };
    auto upd = [&aib](int poz) {
        while (poz < aib.size())
            aib[poz]++, poz += poz & -poz;
    };
    ll rez = 0;
    for (int i = 0; i < ax.size(); i++)
    {
        rez += qr(ax.size() + 2) - qr(ax[i] - 1);
        upd(ax[i]);
    }
    return rez;
}
ll count_swaps(vector<int> v)
{
    int n = (int)v.size();
    unordered_map<int, int> mn, mp, dat;
    unordered_map<int, vector<int>> mm;
    vector<int> ax, rez;
    ax.reserve(n);
    for (size_t i = 0; i < v.size(); i++)
    {
        mm[v[i]].push_back(i);
        if (v[i] > 0)
        {
            if (mn[v[i]] > mp[v[i]])
                mn[v[i]]--;
            else
            {
                mp[v[i]]++;
                rez.push_back(v[i]);
            }
        }
        else
        {
            v[i] = -v[i];
            if (mp[v[i]] > mn[v[i]])
                mp[v[i]]--;
            else
            {
                mn[v[i]]++;
                rez.push_back(v[i]);
            }
            v[i] = -v[i];
        }
    }
    for (auto &i : mm)
        reverse(i.second.begin(), i.second.end());
    for (const auto &i : rez)
    {
        ax.push_back(mm[-i].back() + 1);
        ax.push_back(mm[i].back() + 1);
        mm[-i].pop_back();
        mm[i].pop_back();
    }
    return solve(ax);
}

Compilation message (stderr)

shoes.cpp: In lambda function:
shoes.cpp:14:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   14 |         while (poz < aib.size())
      |                ~~~~^~~~~~~~~~~~
shoes.cpp: In function 'll solve(std::vector<int>&)':
shoes.cpp:18:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   18 |     for (int i = 0; i < ax.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