Submission #728021

#	Time	Username	Problem	Language	Result	Execution time	Memory
728021		aykhn	Prisoner Challenge (IOI22_prison)	C++17	10 / 100	9 ms	872 KiB

prison

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

/*
    author: aykhn
    4/21/2023
*/

using namespace std;

typedef long long ll;

#define OPT ios_base::sync_with_stdio(0); \
            cin.tie(0); \
            cout.tie(0)
#define pii pair<int,int>
#define pll pair<ll,ll>
#define all(v) v.begin(), v.end()
#define mpr make_pair
#define pb push_back
#define ts to_string
#define fi first
#define se second
#define inf 0x3F3F3F3F
#define infll 0x3F3F3F3F3F3F3F3FLL
#define bpc __builtin_popcount
#define print(v) for(int i = 0; i < v.size(); i++) cout << v[i] << " "; cout<<endl;
/*
    notes:
        divide the bits into consecutive pairs
        00 -> 0 = x
        01 -> 1 = x
        10 -> 2 = x
        11 -> 3 = x

        can be look as ab where a = 2 and b = 1 so when turned on += them

        on whiteboard: x*10 + group number

        max group number = lg(MAX)/2 + 1 = lg(5000)/2 + 1 ~~ 12/2 + 1 = 7

        max X = 36 (max 1st group = 1 so 17, 36)

        25 + 1.5*3 + 10 = 36 points
*/

vector<vector<int>> devise_strategy(int n)
{
    vector<vector<int>> s(25, vector<int> (n + 1, 0));

    s[0][0] = 0;
    for (int i = 1; i <= n; i++) s[0][i] = ((i >> 12) & 1)*12 + 12;

    for (int i = 24; i >= 1; i--)
    {
        int pos = i;
        if (i > 12) pos = i - 12;
        s[i][0] = pos%2;

        int y = (i > 12);

        for (int j = 1; j <= n; j++)
        {
            int x = ((j >> (pos)) & 1);

            if (x > y)
            {
                if (pos%2) s[i][j] = -1;
                else s[i][j] = -2;
            }
            else if (x < y)
            {
                if (pos%2) s[i][j] = -2;
                else s[i][j] = -1;
            }
            else
            {
                if (pos - 1 == 0)
                {
                    if (j & 1)
                    {
                        if (pos%2) s[i][j] = -1;
                        else s[i][j] = -2;
                    }
                    else
                    {
                        if (pos%2) s[i][j] = -2;
                        else s[i][j] = -1;
                    }
                }
                else s[i][j] = ((j >> (pos - 1)) & 1)*12 + pos - 1;
            }
        }
    }

    return s;
}

//0 01 00 00 00 00 00
//0 00 11 11 11 10 10

• Subtask 1: 5 / 5
• Subtask 2: 5 / 5
• Subtask 3: 0 / 90