Submission #1072409

#	Time	Username	Problem	Language	Result	Execution time	Memory
1072409		andrei_iorgulescu	Longest Trip (IOI23_longesttrip)	C++17	100 / 100	12 ms	604 KiB

longesttrip

#include <bits/stdc++.h>
#include "longesttrip.h"
#warning That's not FB, that's my FB

using namespace std;

vector<int> longest_trip(int N, int D)
{
    if (D == 3)
    {
        vector<int> ans;
        for (int i = 0; i < N; i++)
            ans.push_back(i);
        return ans;
    }
    if (D == 2)
    {
        deque<int> chn;
        if (are_connected({0}, {1}))
        {
            chn.push_back(0), chn.push_back(1);
            if (are_connected({chn.back()}, {2}))
                chn.push_back(2);
            else
                chn.push_front(2);
        }
        else
        {
            chn.push_back(1);
            chn.push_back(2);
            chn.push_back(0);
        }
        for (int i = 3; i < N; i++)
        {
            if (are_connected({i}, {chn.back()}))
                chn.push_back(i);
            else
                chn.push_front(i);
        }
        vector<int> ans;
        while (!chn.empty())
            ans.push_back(chn.back()), chn.pop_back();
        return ans;
    }
    vector<int> c1, c2;
    c1.push_back(0);
    for (int i = 1; i < N; i += 2)
    {
        if (i + 1 == N)
        {
            bool b1 = are_connected({i}, {c1.back()});
            if (b1)
                c1.push_back(i);
            else
            {
                if (c2.empty())
                    c2.push_back(i);
                else
                {
                    bool b2 = are_connected({i}, {c2.back()});
                    if (b2)
                        c2.push_back(i);
                    else
                    {
                        while (!c2.empty())
                        {
                            c1.push_back(c2.back());
                            c2.pop_back();
                        }
                        c2.push_back(i);
                    }
                }
            }
        }
        else
        {
            bool bb = are_connected({i}, {i + 1});
            if (bb)
            {
                bool b1 = are_connected({i}, {c1.back()});
                if (b1)
                    c1.push_back(i), c1.push_back(i + 1);
                else
                {
                    if (c2.empty())
                        c2.push_back(i), c2.push_back(i + 1);
                    else
                    {
                        bool b2 = are_connected({i}, {c2.back()});
                        if (b2)
                            c2.push_back(i), c2.push_back(i + 1);
                        else
                        {
                            while (!c2.empty())
                            {
                                c1.push_back(c2.back());
                                c2.pop_back();
                            }
                            c2.push_back(i), c2.push_back(i + 1);
                        }
                    }
                }
            }
            else
            {
                bool b1 = are_connected({i}, {c1.back()});
                if (b1)
                {
                    c1.push_back(i);
                    if (c2.empty())
                        c2.push_back(i + 1);
                    else
                    {
                        bool b2 = are_connected({i + 1}, {c2.back()});
                        if (b2)
                            c2.push_back(i + 1);
                        else
                        {
                            while (!c2.empty())
                            {
                                c1.push_back(c2.back());
                                c2.pop_back();
                            }
                            c2.push_back(i + 1);
                        }
                    }
                }
                else
                {
                    c1.push_back(i + 1);
                    if (c2.empty())
                        c2.push_back(i);
                    else
                    {
                        bool b2 = are_connected({i}, {c2.back()});
                        if (b2)
                            c2.push_back(i);
                        else
                        {
                            while (!c2.empty())
                            {
                                c1.push_back(c2.back());
                                c2.pop_back();
                            }
                            c2.push_back(i);
                        }
                    }
                }
            }
        }
    }
    if (c2.empty())
        return c1;
    if (!are_connected(c1, c2))
    {
        if (c1.size() < c2.size())
            swap(c1, c2);
        return c1;
    }
    vector<int> tq1, tq2;
    tq1.push_back(c1[0]);
    if (c1.size() > 1)
        tq1.push_back(c1.back());
    tq2.push_back(c2[0]);
    if (c2.size() > 1)
        tq2.push_back(c2.back());
    bool bb = are_connected(tq1, tq2);
    if (bb)
    {
        if (are_connected({c1[0]}, {c2[0]}))
        {
            reverse(c1.begin(), c1.end());
            for (auto it : c2)
                c1.push_back(it);
            return c1;
        }
        if (are_connected({c1[0]}, {c2.back()}))
        {
            for (auto it : c1)
                c2.push_back(it);
            return c2;
        }
        if (are_connected({c1.back()}, {c2[0]}))
        {
            for (auto it : c2)
                c1.push_back(it);
            return c1;
        }
        reverse(c2.begin(), c2.end());
        for (auto it : c2)
            c1.push_back(it);
        return c1;
    }
    else
    {
        int st = -1, pas = 1 << 7;
        while (pas != 0)
        {
            if (st + pas + 1 < c2.size())
            {
                vector<int> qq;
                for (int i = 0; i <= st + pas; i++)
                    qq.push_back(c2[i]);
                bool lmf = are_connected(c1, qq);
                if (!lmf)
                    st += pas;
            }
            pas /= 2;
        }
        st++;
        int ps2 = st;
        int el2 = c2[st];
        st = -1, pas = 1 << 7;
        while (pas != 0)
        {
            if (st + pas + 1 < c1.size())
            {
                vector<int> qq;
                for (int i = 0; i <= st + pas; i++)
                    qq.push_back(c1[i]);
                bool lmf = are_connected({el2}, qq);
                if (!lmf)
                    st += pas;
            }
            pas /= 2;
        }
        st++;
        int ps1 = st;
        int el1 = c1[st];
        vector<int> ans;
        for (int i = ps1 + 1; ; i++)
        {
            ans.push_back(c1[i % (int)c1.size()]);
            if (i % (int)c1.size() == ps1)
                break;
        }
        for (int i = ps2; ; i++)
        {
            ans.push_back(c2[i % (int)c2.size()]);
            if ((i + 1) % (int)c2.size() == ps2)
                break;
        }
        return ans;
    }
}

Compilation message (stderr)

longesttrip.cpp:3:2: warning: #warning That's not FB, that's my FB [-Wcpp]
    3 | #warning That's not FB, that's my FB
      |  ^~~~~~~
longesttrip.cpp: In function 'std::vector<int> longest_trip(int, int)':
longesttrip.cpp:199:30: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  199 |             if (st + pas + 1 < c2.size())
      |                 ~~~~~~~~~~~~~^~~~~~~~~~~
longesttrip.cpp:216:30: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  216 |             if (st + pas + 1 < c1.size())
      |                 ~~~~~~~~~~~~~^~~~~~~~~~~
longesttrip.cpp:229:13: warning: unused variable 'el1' [-Wunused-variable]
  229 |         int el1 = c1[st];
      |             ^~~

• Subtask 0: 0 / 0
• Subtask 1: 5 / 5
• Subtask 2: 10 / 10
• Subtask 3: 25 / 25
• Subtask 4: 60 / 60