Submission #599644

#	Time	Username	Problem	Language	Result	Execution time	Memory
599644		fvogel499	Flight to the Ford (BOI22_communication)	C++17	15 / 100	136 ms	118784 KiB

communication

#include <cassert>
#include "communication.h"
#include <vector>
#include <set>
#include <iostream>

//
// --- Sample implementation for the task communication ---
//
// To compile this program with the sample grader, place:
//     communication.h communication_sample.cpp sample_grader.cpp
// in a single folder, then open the terminal in this directory (right-click onto an empty spot in the directory,
// left click on "Open in terminal") and enter e.g.:
//     g++ -std=c++17 communication_sample.cpp sample_grader.cpp
// in this folder. This will create a file a.out in the current directory which you can execute from the terminal
// as ./a.out
// See task statement or sample_grader.cpp for the input specification
//

std::vector<int> getGroup(std::vector<int> receipt = {}) {
    std::vector<int> over;
    for (int i = 0; i < (1<<4); i++) if (__builtin_popcount(i) <= 1) over.push_back(i);
    over.push_back(1+4);
    over.push_back(1+8);
    over.push_back(2+8);
    std::vector<int> who [1<<4];
    for (int i : over) who[i].push_back(1);
    for (int i : over) who[i^(1+2+4+8)].push_back(2);
    for (int i : over) who[i^(1+8)].push_back(3);
    for (int i = 0; i < (1<<4); i++) {
        while ((int)(who[i].size()) < 2) {
            who[i].push_back(1);
        }
    }
    int comp = 0;
    for (int i = 0; i < 4; i++) {
        int u = receipt.empty() ? receive() : receipt[i];
        if (u) {
            comp |= (1<<i);
        }
    }
    return who[comp];
}

std::vector<int> setGroup(int x) {
    std::vector<int> loc;
    if (x == 1) {
        loc.push_back(send(0));
        loc.push_back(send(0));
        loc.push_back(send(0));
        loc.push_back(send(0));
    }
    else if (x == 2) {
        loc.push_back(send(1));
        loc.push_back(send(1));
        loc.push_back(send(1));
        loc.push_back(send(1));
    }
    else {
        loc.push_back(send(1));
        loc.push_back(send(0));
        loc.push_back(send(0));
        loc.push_back(send(1));
    }
    return getGroup(loc);
}

void setRec(std::vector<int> gr, int x) {
    assert(!gr.empty());
    if (gr.size() <= 2) {
        return;
    }
    std::vector<int> sp [3];
    int whereIsX = 0;
    for (int i : gr) {
        int mnv = 0;
        for (int j = 0; j < 3; j++) if (sp[j].size() < sp[mnv].size()) mnv = j;
        if (i == x) whereIsX = mnv;
        sp[mnv].push_back(i);
    }
    std::vector<int> resp = setGroup(whereIsX+1);
    std::vector<int> ng;
    for (int i : resp) for (int j : sp[i-1]) {
        ng.push_back(j);
    }
    assert(ng.size() < gr.size());
    setRec(ng, x);
}

std::vector<int> reverseRec(std::vector<int> gr) {
    assert(!gr.empty());
    if (gr.size() <= 2) {
        return gr;
    }
    std::vector<int> sp [3];
    for (int i : gr) {
        int mnv = 0;
        for (int j = 0; j < 3; j++) if (sp[j].size() < sp[mnv].size()) mnv = j;
        sp[mnv].push_back(i);
    }
    std::vector<int> resp = getGroup();
    std::vector<int> ng;
    for (int i : resp) for (int j : sp[i-1]) {
        ng.push_back(j);
    }
    assert(ng.size() < gr.size());
    return reverseRec(ng);
}

void encode(int N, int X) {
    std::vector<int> gr;
    for (int i = 1; i <= N; i++) gr.push_back(i);
    setRec(gr, X);
}

std::pair<int, int> decode(int N) {
    std::vector<int> gr;
    for (int i = 1; i <= N; i++) gr.push_back(i);
    std::vector<int> resp = reverseRec(gr);
    if ((int)(resp.size()) == 1) return std::make_pair(resp[0], 1);
    if ((int)(resp.size()) == 2) return std::make_pair(resp[0], resp[1]);
    assert(false);
    return {1, 1};
}

• Subtask 1: 15 / 15
• Subtask 2: 0 / 85