Submission #1240134

#	Time	Username	Problem	Language	Result	Execution time	Memory
1240134		countless	앵무새 (IOI11_parrots)	C++20	17 / 100	2 ms	840 KiB

encoder

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

typedef long long ll;
typedef long double ld;

#define sp <<" "<<
#define endl "\n"

void encode(int N, int M[]) {
    for (int i = 0; i < N; i++) {
        cerr << M[i] << " ";
    }   cerr << endl;

    vector<int> one, zero;
    for (int i = 0; i < N; i++) {
        for (int j = 0; j < 8; j+=2) {
            int rep = 0;
            if (M[i] & (1 << j)) {
                rep |= (1 << 0);
            }

            if (M[i] & (1 << (j+1))) {
                rep |= (1 << 1);
            }

            int oth = 3 - rep;
            while (rep--) {
                one.push_back((i * 8 + j) / 2);
            }

            while (oth--) {
                zero.push_back((i * 8 + j) / 2);
            }
        }
    }

    if (one.size() < zero.size()) {
        for (auto &x : one) {
            send(x);
        }
    } else {
        for (auto &x : zero) {
            send(x);
        }

        for (int i = 0; i < 4; i++) {
            send(255);
        }
    }
}

decoder

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

typedef long long ll;
typedef long double ld;

#define sp <<" "<<
#define endl "\n"

void decode(int N, int L, int X[]) {
    vector<int> cnt(256);

    for (int i = 0; i < L; i++) {
        cnt[X[i]]++;
    }

    bool flip = false;
    if (cnt[255] >= 4) {
        cnt[255] -= 4;
        flip = true;
    }

    vector<int> M(N, 0);

    for (int i = 0; i < 256; i++) {
        int j = i * 2;
        int pos = j / 8, bit = j % 8;
        if (cnt[i] & (1 << 0)) {
            M[pos] |= (1 << bit);
        }

        if (cnt[i] & (1 << 1)) {
            M[pos] |= (1 << (bit+1));
        }
    }

    if (flip) {
        for (int i = 0; i < N; i++) {
            M[i] = ~M[i];
        }
    }

    for (auto &x : M) {
        output(x);
    }
}

• Subtask 1: 17 / 17
• Subtask 2: 0 / 17
• Subtask 3: 0 / 18
• Subtask 4: 0 / 29
• Subtask 5: 0 / 19