Submission #950817

#	Time	Username	Problem	Language	Result	Execution time	Memory
950817		Dec0Dedd	Prisoner Challenge (IOI22_prison)	C++17	56 / 100	14 ms	1300 KiB

prison

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

using namespace std;

typedef long long ll;
typedef pair<int, int> pii;

const int K = 13;

vector<vector<int>> devise_strategy(int n) {
    vector<vector<int>> res(2*K+1, vector<int>(n+1, 0));

    // 2*i+1 - ith bit set
    // 2*i+2 - ith bit not set

    // for i=0, 2, 4, ... we check in A
    // for i=1, 3, 5, ... we check in B

    res[0][0]=(K-1)%2;
    for (int i=1; i<=n; ++i) {
        int x=K-1;
        if (i&(1<<x)) res[0][i]=2*x+1;
        else res[0][i]=2*x+2;
    }

    for (int i=0; i<K; ++i) {
        int s=2*i+1;

        if (i%2 == 0) {
            res[s][0]=1; // we know ith bit of A so we need to check B
            for (int j=1; j<=n; ++j) {
                if (j&(1<<i)) {
                    int x=i-1;
                    if (j&(1<<x)) res[s][j]=2*x+1;
                    else res[s][j]=2*x+2;
                } else res[s][j]=-2;
            }
        } else {
            res[s][0]=0;
            for (int j=1; j<=n; ++j) {
                if (j&(1<<i)) {
                    int x=i-1;
                    if (j&(1<<x)) res[s][j]=2*x+1;
                    else res[s][j]=2*x+2;
                } else res[s][j]=-1;
            }
        }

        s=2*i+2;
        if (i%2 == 0) {
            res[s][0]=1;
            for (int j=1; j<=n; ++j) {
                if (j&(1<<i)) res[s][j]=-1;
                else {
                    int x=i-1;
                    if (j&(1<<x)) res[s][j]=2*x+1;
                    else res[s][j]=2*x+2;
                }
            }
        } else {
            res[s][0]=0;
            for (int j=1; j<=n; ++j) {
                if (j&(1<<i)) res[s][j]=-2;
                else {
                    int x=i-1;
                    if (j&(1<<x)) res[s][j]=2*x+1;
                    else res[s][j]=2*x+2;
                }
            }
        }
    }

    //cout<<"size "<<res.size()<<"\n";
    return res;
}

• Subtask 1: 5 / 5
• Subtask 2: 5 / 5
• Subtask 3: 46 / 90