Submission #628767

#	Time	Username	Problem	Language	Result	Execution time	Memory
628767		tutis	Prisoner Challenge (IOI22_prison)	C++17	60 / 100	16 ms	1200 KiB

prison

#include "prison.h"
#include <bits/stdc++.h>
using namespace std;
std::vector<std::vector<int>> devise_strategy(int N) {
    vector<vector<int>>ret;
    vector<pair<int, int>>S = {{1, N}};
    vector<pair<int, int>>S_;
    bool fst = true;
    while (!S.empty())
    {
        S_ = {};
        int x = (int)ret.size();
        int mx = 0;
        ret.push_back(vector<int>(N + 1, 0));
        if (fst == false)
        {
            for (int i = 0; i < (int)S.size(); i++)
            {
                int lo = S[i].first;
                int hi = S[i].second;
                ret[x][lo] = -1;
                ret[x][hi] = -2;
                lo++;
                hi--;
                if (lo <= hi)
                    S_.push_back({lo, hi});
            }
            S = S_;
            S_ = {};
        }
        if (S.empty())
            break;
        for (int i = 0; i < (int)S.size(); i++)
        {
            int lo = S[i].first;
            int hi = S[i].second;
            lo++;
            hi--;
            mx = max(mx, hi - lo + 1);
        }
        if (mx >= 7)
        {
            for (int t = 0; t < 4; t++)
                ret.push_back(vector<int>(N + 1, 0));
            for (int t = 0; t < 4; t++)
                ret[x + 1 + t][0] = 1;
            vector<int>&v = ret[x];
            v[0] = 0;
            for (int i = 0; i < (int)S.size(); i++)
            {
                int lo = S[i].first;
                int hi = S[i].second;
                v[lo] = -1;
                v[hi] = -2;
                lo++;
                hi--;
                int sz = hi - lo + 1;
                if (sz >= 1)
                {
                    int k = (sz + 3) / 4;
                    k = max(k, 2);
                    for (int t = 0; t < 4; t++)
                    {
                        int l = lo + t * k;
                        int r = lo + (t + 1) * k - 1;
                        r = min(r, hi);
                        if (l <= r)
                        {
                            for (int i = l; i <= r; i++)
                            {
                                ret[(x + 1) + t][i] = x + 5;
                                v[i] = x + 1 + t;
                            }
                            for (int i = lo - 1; i <= l; i++)
                            {
                                ret[(x + 1) + t][i] = -2;
                            }
                            for (int i = r; i <= hi + 1; i++)
                            {
                                ret[(x + 1) + t][i] = -1;
                            }
                            if (r - l + 1 > 2)
                            {
                                S_.push_back({l, r});
                            }
                        }
                    }
                }
            }
            S = S_;
        }
        else if (mx >= 5)
        {
            for (int t = 0; t < 3; t++)
                ret.push_back(vector<int>(N + 1, 0));
            for (int t = 0; t < 3; t++)
                ret[x + 1 + t][0] = 1;
            vector<int>&v = ret[x];
            v[0] = 0;
            for (int i = 0; i < (int)S.size(); i++)
            {
                int lo = S[i].first;
                int hi = S[i].second;
                v[lo] = -1;
                v[hi] = -2;
                lo++;
                hi--;
                int sz = hi - lo + 1;
                if (sz >= 1)
                {
                    int k = (sz + 2) / 3;
                    k = max(k, 2);
                    for (int t = 0; t < 3; t++)
                    {
                        int l = lo + t * k;
                        int r = lo + (t + 1) * k - 1;
                        r = min(r, hi);
                        if (l <= r)
                        {
                            for (int i = l; i <= r; i++)
                            {
                                ret[(x + 1) + t][i] = x + 4;
                                v[i] = x + 1 + t;
                            }
                            for (int i = lo - 1; i <= l; i++)
                            {
                                ret[(x + 1) + t][i] = -2;
                            }
                            for (int i = r; i <= hi + 1; i++)
                            {
                                ret[(x + 1) + t][i] = -1;
                            }
                            if (r - l + 1 > 2)
                            {
                                S_.push_back({l, r});
                            }
                        }
                    }
                }
            }
            S = S_;
        }
        else if (mx >= 3)
        {
            for (int t = 0; t < 2; t++)
                ret.push_back(vector<int>(N + 1, 0));
            for (int t = 0; t < 2; t++)
                ret[x + 1 + t][0] = 1;
            vector<int>&v = ret[x];
            v[0] = 0;
            for (int i = 0; i < (int)S.size(); i++)
            {
                int lo = S[i].first;
                int hi = S[i].second;
                v[lo] = -1;
                v[hi] = -2;
                lo++;
                hi--;
                int sz = hi - lo + 1;
                if (sz >= 1)
                {
                    int k = (sz + 1) / 2;
                    k = max(k, 2);
                    for (int t = 0; t < 2; t++)
                    {
                        int l = lo + t * k;
                        int r = lo + (t + 1) * k - 1;
                        r = min(r, hi);
                        if (l <= r)
                        {
                            for (int i = l; i <= r; i++)
                            {
                                ret[(x + 1) + t][i] = x + 3;
                                v[i] = x + 1 + t;
                            }
                            for (int i = lo - 1; i <= l; i++)
                            {
                                ret[(x + 1) + t][i] = -2;
                            }
                            for (int i = r; i <= hi + 1; i++)
                            {
                                ret[(x + 1) + t][i] = -1;
                            }
                            if (r - l + 1 > 2)
                            {
                                S_.push_back({l, r});
                            }
                        }
                    }
                }
            }
            S = S_;
        }
        else if (mx >= 1)
        {
            for (int t = 0; t < 1; t++)
                ret.push_back(vector<int>(N + 1, 0));
            for (int t = 0; t < 1; t++)
                ret[x + 1 + t][0] = 1;
            vector<int>&v = ret[x];
            v[0] = 0;
            for (int i = 0; i < (int)S.size(); i++)
            {
                int lo = S[i].first;
                int hi = S[i].second;
                v[lo] = -1;
                v[hi] = -2;
                lo++;
                hi--;
                int sz = hi - lo + 1;
                if (sz >= 1)
                {
                    int k = (sz + 1) / 1;
                    k = max(k, 2);
                    for (int t = 0; t < 1; t++)
                    {
                        int l = lo + t * k;
                        int r = lo + (t + 1) * k - 1;
                        r = min(r, hi);
                        if (l <= r)
                        {
                            for (int i = l; i <= r; i++)
                            {
                                ret[(x + 1) + t][i] = x + 2;
                                v[i] = x + 1 + t;
                            }
                            for (int i = lo - 1; i <= l; i++)
                            {
                                ret[(x + 1) + t][i] = -2;
                            }
                            for (int i = r; i <= hi + 1; i++)
                            {
                                ret[(x + 1) + t][i] = -1;
                            }
                            if (r - l + 1 > 2)
                            {
                                S_.push_back({l, r});
                            }
                        }
                    }
                }
            }
            S = S_;
        }
        else
        {
            vector<int>&v = ret[x];
            v[0] = 0;
            for (int i = 0; i < (int)S.size(); i++)
            {
                int lo = S[i].first;
                int hi = S[i].second;
                v[lo] = -1;
                v[hi] = -2;
            }
            S = S_;
        }
        int x1 = ret.size();
        fst = false;
        //cout << mx << " " << x1 - x << endl;
    }
    int mx = (int)ret.size() - 1;
    for (vector<int> &i : ret)
        for (int &j : i)
            j = min(j, mx);
    return ret;
}

Compilation message (stderr)

prison.cpp: In function 'std::vector<std::vector<int> > devise_strategy(int)':
prison.cpp:258:13: warning: unused variable 'x1' [-Wunused-variable]
  258 |         int x1 = ret.size();
      |             ^~

• Subtask 1: 5 / 5
• Subtask 2: 5 / 5
• Subtask 3: 50 / 90