Submission #979759

#	Time	Username	Problem	Language	Result	Execution time	Memory
979759		sleepntsheep	Prisoner Challenge (IOI22_prison)	C++17	10 / 100	7 ms	860 KiB

prison

#include "prison.h"
//#include<cstdio>

#include <vector>

std::vector<std::vector<int>> devise_strategy(int N) {

    /*
     * compare digits-by-digits
     *
     * On base B, this happens ln(N)/ln(B) iterations
     * each iterations need B place to store the result,
     * and another to denotes that one need to check the next bits
     * f(B) = (B + 1) * ln(N) / ln (B) 
     */

    constexpr int B = 4, X = 31;
    std::vector<std::vector<int> > s(X+1, std::vector<int>(N+1));

    auto get = [&](int x, int i)
    {
        while(i--) x/=B;
        return x%B;
    };

    for(int read=0;read<=X;++read)
    {
        auto write = [&](int j,int x) { s[read][j] = x; };

        int at=(read)/(B+1);
        int dd=(read)%(B+1);
        if(dd>0)
        {
            write(0, 1);
            --dd;
            for(int i=1;i<=N;++i)
            {
                int ee=get(i,at);
                if(ee==dd)
                    write(i, (at)*(B+1));
                else
                    write(i, ee>dd?-1:-2);
            }
        }
        else
        {
            write(0,0);
            for(int i=1;i<=N;++i)
            {
                int to = at ? at - 1 : 6;
                write(i, to*(B+1)+1+get(i,to));
            }
        }
    }

    return s;
}

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