Submission #1060284

#	Time	Username	Problem	Language	Result	Execution time	Memory
1060284		aykhn	Longest Trip (IOI23_longesttrip)	C++17	70 / 100	58 ms	1840 KiB

longesttrip

#include <bits/stdc++.h>
#include "longesttrip.h"
 
using namespace std;
 
map<pair<vector<int>, vector<int>>, int> mp;
 
int ask(vector<int> a, vector<int> b)
{
    if (a.empty() || b.empty()) return 0;
    if (mp.find({a, b}) != mp.end()) return mp[{a, b}];
    return mp[{a, b}] = mp[{b, a}] = are_connected(a, b);
}
 
vector<int> longest_trip(int n, int D)
{
    mp.clear();
    vector<int> v1, v2;
    v1.push_back(0);
    for (int i = 1; i < n; i++)
    {
        if (ask(v1, {i}) && ask(v2, {i})) 
        {
            int id1 = -1, id2 = -1;
            int lx = 0, rx = (int)v1.size() - 1;
            while (lx < rx)
            {
                int m = (lx + rx) >> 1;
                vector<int> q;
                for (int i = lx; i <= m; i++) q.push_back(v1[i]);
                if (ask(q, {i})) rx = m;
                else lx = m + 1;
            }
            id1 = lx;
            lx = 0, rx = (int)v2.size() - 1;
            while (lx < rx)
            {
                int m = (lx + rx) >> 1;
                vector<int> q;
                for (int i = lx; i <= m; i++) q.push_back(v2[i]);
                if (ask(q, {i})) rx = m;
                else lx = m + 1;
            }
            id2 = lx;
            vector<int> nw;
            for (int j = (id2 + 1) % v2.size(); 1; j = (j + 1) % v2.size())
            {
                nw.push_back(v2[j]);
                if (j == id2) break;
            }
            nw.push_back(i), nw.push_back(v1[id1]);
            for (int j = (id1 + 1) % v1.size(); j != id1; j = (j + 1) % v1.size())
            {
                nw.push_back(v1[j]);
            }
            v2.clear();
            v1 = nw;
        }
        else if (ask(v1, {i})) 
        {
            vector<int> nw;
            if (ask({v1.back()}, {i}))
            {
                nw = v1;
                nw.push_back(i);
            }
            else
            {
                int l = 0, r = (int)v1.size() - 1;
                while (l < r)
                {
                    int mid = (l + r) >> 1;
                    vector<int> x;
                    for (int j = 0; j <= mid; j++)
                    {
                        x.push_back(v1[j]);
                    }
                    if (ask(x, {i})) r = mid;
                    else l = mid + 1;
                }
                int idx = l;
                nw.push_back(i), nw.push_back(v1[idx]);
                for (int j = (idx + 1) % v1.size(); j != idx; j = (j + 1) % v1.size())
                {
                    nw.push_back(v1[j]);
                }
            }
            v1 = nw;
        }
        else if (ask(v2, {i}))
        {
            vector<int> nw;
            if (ask({v2.back()}, {i}))
            {
                nw = v2;
                nw.push_back(i);
            }
            else
            {
                int l = 0, r = (int)v2.size() - 1;
                while (l < r)
                {
                    int mid = (l + r) >> 1;
                    vector<int> x;
                    for (int j = 0; j <= mid; j++)
                    {
                        x.push_back(v2[j]);
                    }
                    if (ask(x, {i})) r = mid;
                    else l = mid + 1;
                }
                int idx = l;
                nw.push_back(i), nw.push_back(v2[idx]);
                for (int j = (idx + 1) % v2.size(); j != idx; j = (j + 1) % v2.size())
                {
                    nw.push_back(v2[j]);
                }
            }
            v2 = nw;
        }
        else v2.push_back(i);
    }
    if (v1.size() > v2.size()) return v1;
    else return v2;
};

• Subtask 0: 0 / 0
• Subtask 1: 5 / 5
• Subtask 2: 10 / 10
• Subtask 3: 25 / 25
• Subtask 4: 30 / 60