Submission #628373

#	Time	Username	Problem	Language	Result	Execution time	Memory
628373		dqhungdl	Prisoner Challenge (IOI22_prison)	C++17	65 / 100	19 ms	1140 KiB

prison

#include "prison.h"
#include <bits/stdc++.h>
using namespace std;

typedef pair<int, int> ii;
const int MAX_BIT = 12;
int cnt = 0, id[13][2];
ii rev[25];

int getBit(int x, int k) {
    return (x >> k) & 1;
}

vector<vector<int>> devise_strategy(int N) {
    vector<int> V;
    for (int i = 1; i <= MAX_BIT; i++)
        for (int j = 0; j <= 1; j++) {
            id[i][j] = ++cnt;
            rev[cnt] = {i, j};
        }
    vector<vector<int>> rs(cnt + 1, vector<int>(N + 1));
    for (int i = 1; i <= N; i++)
        rs[0][i] = id[MAX_BIT][getBit(i, MAX_BIT)];
    for (int i = 1; i <= cnt; i++) {
        int bit = rev[i].first, val = rev[i].second;
        rs[i][0] = 1 - (MAX_BIT - bit) % 2;
        for (int j = 1; j <= N; j++) {
            if (getBit(j, bit) < val)
                rs[i][j] = (rs[i][0] ? -2 : -1);
            else if (getBit(j, bit) > val)
                rs[i][j] = (rs[i][0] ? -1 : -2);
            else {
                if (bit == 1) {
                    if (!getBit(j, 0))
                        rs[i][j] = (rs[i][0] ? -2 : -1);
                    else
                        rs[i][j] = (rs[i][0] ? -1 : -2);
                } else
                    rs[i][j] = id[bit - 1][getBit(j, bit - 1)];
            }
        }
    }
    return rs;
}

/********************************************************************/
//static constexpr int kNumPrisoners = 500;
//
//static void invalid_strategy(string message) {
//    printf("%s\n", message.c_str());
//    exit(0);
//}
//
//int main() {
//    freopen("../_input", "r", stdin);
//    int N;
//    assert(1 == scanf("%d", &N));
//
//    vector<vector<int>> strategy = devise_strategy(N);
//    if (strategy.size() == 0) {
//        invalid_strategy("s is an empty array");
//    }
//    int x = strategy.size() - 1;
//    for (int i = 0; i <= x; ++i) {
//        if (static_cast<int>(strategy[i].size()) != N + 1) {
//            invalid_strategy("s[i] contains incorrect length");
//        }
//        if (strategy[i][0] < 0 || strategy[i][0] > 1) {
//            invalid_strategy("First element of s[i] is non-binary");
//        }
//        for (int j = 1; j <= N; ++j) {
//            if (strategy[i][j] < -2 || strategy[i][j] > x) {
//                invalid_strategy("s[i][j] contains incorrect value");
//            }
//        }
//    }
//
//    FILE *log_file = fopen("log.txt", "w");
//
//    int A, B;
//    while (1 == scanf("%d", &A) && A != -1) {
//        assert(1 == scanf("%d", &B));
//        bool answer = false;
//        int whiteboard = 0;
//        for (int i = 0; i < kNumPrisoners && !answer; ++i) {
//            int check = strategy[whiteboard][0];
//            whiteboard = strategy[whiteboard][check == 0 ? A : B];
//            if (whiteboard < 0) {
//                answer = true;
//                printf("%c\n", "BA"[whiteboard + 2]);
//            } else {
//                if (i > 0) {
//                    fprintf(log_file, " ");
//                }
//                fprintf(log_file, "%d\n", whiteboard);
//                fprintf(log_file, " (%d, %d)\n", rev[whiteboard].first, rev[whiteboard].second);
//            }
//        }
//        if (!answer) {
//            printf("X\n");
//        }
//        fprintf(log_file, "\n");
//        fflush(log_file);
//    }
//}

• Subtask 1: 5 / 5
• Subtask 2: 5 / 5
• Subtask 3: 55 / 90