Submission #97200

#	Time	Username	Problem	Language	Result	Execution time	Memory
97200		Alexa2001	Parrots (IOI11_parrots)	C++17	98 / 100	15 ms	1792 KiB

encoder

#include "encoder.h"
#include "encoderlib.h"
#include <bits/stdc++.h>

using namespace std;

void encode(int N, int M[])
{
    vector<int> bits;
    int i, j;
    for(i=0; i<N; ++i)
        for(j=0; j<8; ++j)
            bits.push_back((M[i] >> j)&1);

    int cnt = 0;
    for(i=0; 2*i<bits.size(); ++i)
    {
        int a, b;
        a = bits[2*i];
        b = bits[2*i+1];

        if(a == 0) cnt += 1;
        if(b == 0) cnt += 2;
    }

    bool rev = (cnt > 6*N);

    for(i=0; 2*i<bits.size(); ++i)
    {
        int a, b;
        a = bits[2*i];
        b = bits[2*i+1];

        if(a == rev) send(i);
        if(b == rev)
        {
            send(i);
            send(i);
        }
    }

    if(rev)
    {
        send(0); send(0); send(0); send(0);
    }
}

decoder

#include "decoder.h"
#include "decoderlib.h"
#include <bits/stdc++.h>

using namespace std;

static int cnt[300];

void decode(int N, int L, int X[])
{
    memset(cnt, 0, sizeof(cnt));
    int i, j;
    for(i=0; i<L; ++i) ++cnt[X[i]];

    bool rev = 0;
    if(cnt[0] >= 4) rev = 1, cnt[0] -= 4;
    vector<int> bits(8*N, rev ^ 1);

    for(i=0; i<4*N; ++i)
    {
        if(cnt[i] & 1) bits[2*i] = rev;
        if(cnt[i] & 2) bits[2*i+1] = rev;
    }

    for(i=0; i<N; ++i)
    {
        int x = 0;
        for(j=0; j<8; ++j)
            x += (1<<j) * bits[8*i+j];
        output(x);
    }
}

Compilation message (stderr)

encoder.cpp: In function 'void encode(int, int*)':
encoder.cpp:16:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(i=0; 2*i<bits.size(); ++i)
              ~~~^~~~~~~~~~~~
encoder.cpp:28:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(i=0; 2*i<bits.size(); ++i)
              ~~~^~~~~~~~~~~~

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