Submission #630426

#	Time	Username	Problem	Language	Result	Execution time	Memory
630426		garam1732	Prisoner Challenge (IOI22_prison)	C++17	100 / 100	13 ms	1212 KiB

prison

#include "prison.h"

#include <iostream>
#include <vector>
#include <cstring>
using namespace std;

int a[6] = {1667, 555, 185, 61, 20, 6};
int d[5050][10];

int f(int x, int t) {
    if(d[x][t] != -1) return d[x][t];
    if(t == 0) return d[x][t] = x;

    int y = f(x, t-1);
    if(y > 9998) return d[x][t] = y;

    y %= a[t-1];
    if(y == 0) return d[x][t] = 9999;
    if(y == a[t-1]-1) return d[x][t] = 10000;

    return d[x][t] = y-1;
}

std::vector<std::vector<int>> devise_strategy(int N) {
    vector<vector<int> > v(21);
    memset(d, -1, sizeof d);

    v[0].resize(N+1);
    v[0][0] = 0;
    for(int j = 1; j <= N; j++) {
        v[0][j] = j/a[0] + 1;
    }

    for(int i = 1; i < 19; i++) {
        v[i].resize(N+1);

        v[i][0] = (i+2)/3%2;
        int q = (i-1)/3, r = (i-1)%3;
        for(int j = 1; j <= N; j++) {
            int x = f(j, q);
            if(x == 9999) {
                v[i][j] = -1-v[i][0];
                continue;
            }
            else if(x == 10000) {
                v[i][j] = v[i][0]-2;
                continue;
            }

            int y = x / a[q], z = x % a[q];
            if(r < y) v[i][j] = v[i][0]-2;
            else if(r > y) v[i][j] = -1-v[i][0];
            else {
                if(z == 0) v[i][j] = -1-v[i][0];
                else if(z == a[q]-1) v[i][j] = v[i][0]-2;
                else {
                    if(q < 5) v[i][j] = (z-1)/a[q+1] + 1 + 3*(q+1);
                    else v[i][j] = 19 + (z > 2);
                }
            }
        }
    }

    for(int i = 19; i < 21; i++) {
        v[i].resize(N+1);
        v[i][0] = 1;

        int t = i-19;
        for(int j = 1; j <= N; j++) {
            int x = f(j, 6);
            if(x == 9999) v[i][j] = -2;
            else if(x == 10000) v[i][j] = -1;
            else {
                if(t < x/2) v[i][j] = -1;
                else if(t > x/2) v[i][j] = -2;
                else if(x % 2) v[i][j] = -1;
                else v[i][j] = -2;
            }
        }
    }

    return v;
}

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