Submission #1234976

#	Time	Username	Problem	Language	Result	Execution time	Memory
1234976		Hanksburger	Permutation Game (APIO25_permgame)	C++20	16 / 100	10 ms	328 KiB

permgame

#include "permgame.h"
#include <bits/stdc++.h>
using namespace std;
vector<vector<int> > perm;
vector<int> adj[405], vec;
int ans, initans;
bool cmp(vector<int> &vec1, vector<int> &vec2)
{
    if (vec1.size()==4)
        return 1;
    if (vec2.size()==4)
        return 0;
    return vec1.size()>vec2.size(); // beware of inequality direction
}
void computePerm(vector<int> P)
{
    int visited[405]={};
    ans=0;
    perm.clear();
    for (int i=0; i<P.size(); i++)
    {
        if (visited[i])
            continue;
        vector<int> tmp;
        int cur=i;
        while (!visited[cur])
        {
            tmp.push_back(cur);
            visited[cur]=1;
            cur=P[cur];
        }
        if (tmp.size()==1)
            ans++;
        else
            perm.push_back(tmp);
    }
    sort(perm.begin(), perm.end(), cmp); // DONT FORGET THIS NEW ADDITION
}
int Alice(int M, int E, vector<int> U, vector<int> V, int N, vector<int> P)
{
    for (int i=0; i<E; i++)
    {
        adj[U[i]].push_back(V[i]);
        adj[V[i]].push_back(U[i]);
    }
    vec.push_back(0);
    for (int i=1; i<M; i++)
    {
        if (i==1)
            vec.push_back(adj[vec[i-1]][0]);
        else
        {
            int pre=vec[i-2];
            if (adj[vec[i-1]][0]==pre)
                vec.push_back(adj[vec[i-1]][1]);
            else
                vec.push_back(adj[vec[i-1]][0]);
        }
    }
    computePerm(P);
    initans=ans;
    for (int i=0; i<M; i++)
        if (adj[i].size()>=3)
            return ans;
    while (1)
    {
        int updated=0, sum=0;
        for (int i=0; i<perm.size(); i++)
        {
            sum+=perm[i].size();
            if (sum>=M)
            {
                updated=1;
                vector<int> tmp(M);
                int cnt=0;
                for (int j=0; j<=i; j++)
                {
                    for (int x:perm[j])
                    {
                        tmp[vec[cnt]]=x;
                        cnt++;
                        if (cnt==M)
                            break;
                    }
                    if (cnt==M)
                        break;
                }
                int edge=Bob(tmp);
                swap(P[tmp[U[edge]]], P[tmp[V[edge]]]);
                computePerm(P);
                break;
            }
        }
        if (!updated)
            break;
    }
    return max(initans, N-M+1);
}

• Subtask 0: 0 / 0
• Subtask 1: 0 / 6
• Subtask 2: 6 / 6
• Subtask 3: 10 / 10
• Subtask 4: 0 / 24
• Subtask 5: 0 / 24
• Subtask 6: 0 / 30