Submission #958061

#	Time	Username	Problem	Language	Result	Execution time	Memory
958061		Nelt	Longest Trip (IOI23_longesttrip)	C++17	15 / 100	767 ms	2372 KiB

longesttrip

#include "longesttrip.h"
#pragma GCC optimize("O3,unroll-loops")
#pragma GCC target("avx,avx2,fma,popcnt")

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>

/* DEFINES */
#define S second
#define F first
#define ll long long
#define ull unsigned long long
#define ld long double
#define npos ULLONG_MAX
#define INF LLONG_MAX
#define vv(a) vector<a>
#define ss(a) set<a>
#define pp(a, b) pair<a, b>
#define mm(a, b) map<a, b>
#define qq(a) queue<a>
#define pq(a) priority_queue<a>
#define ump(a, b) unordered_map<a, b>
#define ANDROID                   \
    ios_base::sync_with_stdio(0); \
    cin.tie(0);                   \
    cout.tie(0);
#define allc(a) begin(a), end(a)
#define all(a) a, a + sizeof(a) / sizeof(a[0])
#define elif else if
#define endl "\n"
#define pb push_back
#define ins insert
#define logi __lg
#define sqrt sqrtl
#define mpr make_pair
using namespace std;
using namespace __cxx11;
using namespace __gnu_pbds;
typedef char chr;
typedef basic_string<chr> str;
template <typename T, typename key = less<T>>
using ordered_set = tree<T, null_type, key, rb_tree_tag, tree_order_statistics_node_update>;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
const ll N = 256;
vv(ll) g[N];
bool mat[N][N];
std::vector<int> longest_trip(int n, int d)
{
    for (ll i = 0; i < n; i++)
        for (ll j = 0; j < n; j++)
            mat[i][j] = 0;
    for (ll i = 0; i < n; i++)
        g[i].clear();
    vv(int) ans;
    if (d == 3)
    {
        for (ll i = 0; i < n; i++)
            ans.pb(i);
        return ans;
    }
    if (d == 2)
    {
        for (int i = 0; i < n; i++)
            for (int j = i + 1; j < n; j++)
                if (are_connected({i}, {j}))
                    g[i].pb(j), g[j].pb(i), mat[i][j] = mat[j][i] = true;
        vector<int> ans;
        ll found = 0;
        for (ll i = 0; i + 1 < n; i++)
            if (mat[i][i + 1])
            {
                ans.push_back(i), ans.push_back(i + 1), found = i;
                break;
            }
        for (ll i = 0; i < n; i++)
            if (i != found and i != found + 1)
            {
                if (mat[ans.front()][i])
                    ans.insert(ans.begin(), i);
                else
                    ans.push_back(i);
            }
        return ans;
    }
    vector<int> comp, comp1;
    ll p[n];
    iota(p, p + n, 0);
    // shuffle(p, p + n, rng);
    for (int i : p)
        if (comp1.empty())
        {
            if (comp.empty())
            {
                comp = {i};
                continue;
            }
            if (!are_connected({comp.back()}, {i}))
                comp1 = {i};
            else
                comp.push_back(i);
        }
        else
        {
            bool ok = are_connected({comp.back()}, {i});
            if (ok)
            {
                bool ok1 = are_connected({comp1.back()}, {i});
                if (ok1)
                {
                    comp.push_back(i);
                    for (ll j : comp1)
                        comp.push_back(j);
                    comp1.clear();
                }
                else
                    comp.push_back(i);
            }
            else
                comp1.push_back(i);
        }
    // cout << "OK";
    if (comp1.empty())
        return comp;
    if (comp.size() > comp1.size())
        swap(comp, comp1);
    if (!are_connected(comp, comp1))
        return comp1;
    if (comp.size() >= 3)
    {
        bool ok = are_connected({comp.front()}, {comp.back()});
        if (!ok)
        {
            ans = comp;
            if (!are_connected({comp.back()}, {comp1.front()}))
                reverse(ans.begin(), ans.end());
            for (ll i : comp1)
                ans.push_back(i);
            return ans;
        }
        swap(comp, comp1);
        ok = are_connected({comp.front()}, {comp.back()});
        if (!ok)
        {
            ans = comp;
            if (!are_connected({comp.back()}, {comp1.front()}))
                reverse(ans.begin(), ans.end());
            for (ll i : comp1)
                ans.push_back(i);
            return ans;
        }
        swap(comp, comp1);
    }
    ll l = 0, r = comp.size() - 1;
    int first = comp.size() - 1;
    vector<int> tmp;
    while (l <= r)
    {
        tmp.clear();
        ll mid = (l + r) >> 1;
        for (ll i = 0; i <= mid; i++)
            tmp.push_back(comp[i]);
        if (are_connected(tmp, comp1))
            r = mid - 1, first = mid;
        else
            l = mid + 1;
    }
    l = 0, r = comp1.size() - 1;
    int second = comp1.size() - 1;
    while (l <= r)
    {
        tmp.clear();
        ll mid = (l + r) >> 1;
        for (ll i = 0; i <= mid; i++)
            tmp.push_back(comp1[i]);
        if (are_connected({comp[first]}, tmp))
            r = mid - 1, second = mid;
        else
            l = mid + 1;
    }
    for (ll i = first + comp.size() - 1; i >= first; i--)
        ans.push_back(comp[i % comp.size()]);
    for (ll i = second; i < second + comp1.size(); i++)
        ans.push_back(comp1[i % comp1.size()]);
    return ans;
}

Compilation message (stderr)

longesttrip.cpp: In function 'std::vector<int> longest_trip(int, int)':
longesttrip.cpp:183:27: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  183 |     for (ll i = second; i < second + comp1.size(); i++)
      |                         ~~^~~~~~~~~~~~~~~~~~~~~~~

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