Submission #706369

#	Time	Username	Problem	Language	Result	Execution time	Memory
706369		danikoynov	Thousands Islands (IOI22_islands)	C++17	6.75 / 100	33 ms	6964 KiB

islands

#include "islands.h"

#include <variant>
#include <vector>

using namespace std;

const int maxn = 1010;
int edge_index[maxn][maxn], deg[maxn];
std::variant<bool, std::vector<int>> find_journey(
                                      int N, int M, std::vector<int> U, std::vector<int> V)
{

bool spec = true;
for (int i = 0; i < M; i += 2)
{
    if (V[i] != U[i + 1] || U[i] != V[i + 1])
    spec = false;
}
    if (N == 2)
    {

        int cnt0 = 0, cnt1 = 0;
        vector < int > idx0, idx1;
        for (int i = 0; i < M; i ++)
        {
            if (U[i] == 0)
                cnt0 ++, idx0.push_back(i);
            else
                cnt1 ++, idx1.push_back(i);
        }

        if (cnt0 >= 2 && cnt1 >= 1)
        {
            vector < int > path;
            path.push_back(idx0[0]);
            path.push_back(idx1[0]);
            path.push_back(idx0[1]);
            path.push_back(idx0[0]);
            path.push_back(idx1[0]);
            path.push_back(idx0[1]);
            return path;
        }
        return false;
    }
    else
        if (spec)
    {
        for (int i = 0; i < M; i ++)
        {
            if (U[i] == 0)
                deg[0] ++;
        }
        if (deg[0] == 1)
            return false;
        return true;
    }
    else
    {
        for (int i = 0; i < M; i ++)
            edge_index[U[i]][V[i]] = i;

        vector < int > path;
        path.push_back(edge_index[0][1]);
        path.push_back(edge_index[1][0]);
        path.push_back(edge_index[0][2]);
        path.push_back(edge_index[2][0]);

        path.push_back(edge_index[1][0]);
                path.push_back(edge_index[0][1]);
        path.push_back(edge_index[2][0]);
        path.push_back(edge_index[0][2]);
        return path;
    }
}

• Subtask 1: 5 / 5
• Subtask 2: 1.75 / 5
• Subtask 3: 0 / 21
• Subtask 4: 0 / 24
• Subtask 5: 0 / 45