Submission #927716

#	Time	Username	Problem	Language	Result	Execution time	Memory
927716		aykhn	Longest Trip (IOI23_longesttrip)	C++17	15 / 100	776 ms	1108 KiB

longesttrip

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

using namespace std;

int A[300][300];

int ask(vector<int> a, vector<int> b)
{
    for (int x : a)
    {
        for (int y : b)
        {
            if (A[x][y]) return 1;
        }
    }
    return 0;
}

vector<int> longest_trip(int n, int D)
{
    for (int i = 0; i < n; i++)
    {
        A[i][i] = 1;
        for (int j = i + 1; j < n; j++)
        {
            A[i][j] = A[j][i] = are_connected({i}, {j});
        }
    }
    vector<int> used(n, 0);
    vector<int> v1, v2, cur;
    for (int i = 0; i < 3; i++)
    {
        for (int j = i + 1; j < 3; j++)
        {
            if (ask({i}, {j}))
            {
                v1.push_back(i), v1.push_back(j);
                used[i] = used[j] = 1;
                break;
            }
        }
        if (!v1.empty()) break;
    }
    for (int i = 0; i < n; i++)
    {
        if (used[i]) continue;
        if (!v1.empty() && !v2.empty() && ask(v1, {i}) && ask(v2, {i})) 
        {
            int id1 = -1, id2 = -1;
            for (int j = 0; j < v1.size(); j++)
            {
                if (ask({v1[j]}, {i}))
                {
                    id1 = j;
                    break;
                }
            }
            for (int j = 0; j < v2.size(); j++)
            {
                if (ask({v2[j]}, {i}))
                {
                    id2 = j;
                    break;
                }
            }
            cur.clear();
            for (int j = (id2 + 1) % v2.size(); 1; j = (j + 1) % v2.size())
            {
                cur.push_back(v2[j]);
                if (j == id2) break;
            }
            cur.push_back(i), cur.push_back(v1[id1]);
            for (int j = (id1 + 1) % v1.size(); j != id1; j = (j + 1) % v1.size())
            {
                cur.push_back(v1[j]);
            }
            v2.clear();
            v1 = cur;
        }
        else if (ask(v1, {i})) 
        {
            vector<int> nw;
            int idx = -1;
            for (int j = 0; j < v1.size(); j++) 
            {
                if (ask({i}, {v1[j]})) 
                {
                    idx = j;
                    break;
                }
            }
            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 (v2.empty()) v2.push_back(i);
            else
            {
                vector<int> nw;
                int idx = -1;
                for (int j = 0; j < v2.size(); j++) 
                {
                    if (ask({i}, {v2[j]})) 
                    {
                        idx = j;
                        break;
                    }
                }
                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;
            }
        }
    }
    if (max({v1.size(), v2.size(), cur.size()}) == v1.size()) return v1;
    if (max({v1.size(), v2.size(), cur.size()}) == v2.size()) return v2;
    return cur;
}

Compilation message (stderr)

longesttrip.cpp: In function 'std::vector<int> longest_trip(int, int)':
longesttrip.cpp:51:31: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   51 |             for (int j = 0; j < v1.size(); j++)
      |                             ~~^~~~~~~~~~~
longesttrip.cpp:59:31: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   59 |             for (int j = 0; j < v2.size(); j++)
      |                             ~~^~~~~~~~~~~
longesttrip.cpp:85:31: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   85 |             for (int j = 0; j < v1.size(); j++)
      |                             ~~^~~~~~~~~~~
longesttrip.cpp:107:35: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  107 |                 for (int j = 0; j < v2.size(); j++)
      |                                 ~~^~~~~~~~~~~

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