Submission #422881

#	Time	Username	Problem	Language	Result	Execution time	Memory
422881		pliam	Parrots (IOI11_parrots)	C++14	98 / 100	11 ms	1324 KiB

encoder

#include "encoder.h"
#include "encoderlib.h"

void sendcnt(int a,int x){
  for(int i=0;i<x;i++){
    send(a);
  }
}

void encode(int N, int M[])
{
  //4-ary system
  int cnt1=0,cnt2=0;
  for(int num=0;num<N;num++){
    int tmp=M[num];
    for(int pos=0;pos<4;pos++){
      int cnt=tmp&3;//mod4=mod(2^2), we keep last 2 digits
      cnt1+=cnt;
      cnt2+=(3-cnt);
      tmp>>=2;
    }
  }
  bool change=(cnt2<cnt1);
  if(change) sendcnt(255,4);
  for(int num=0;num<N;num++){
    for(int pos=0;pos<4;pos++){
      int cnt=M[num]&3;//mod4=mod(2^2), we keep last 2 digits
      sendcnt((num<<2)|pos,change?(3-cnt):cnt);
      M[num]>>=2;
    }
  }
}

decoder

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

void decode(int N, int L, int X[])
{
  map<int,int> freq;
  for(int i=0;i<L;i++){
    freq[X[i]]++;
  }
  //4-ary system
  bool change=false;
  if(freq.count(255)){
    if(freq[255]>=4){
      change=true;
      freq[255]-=4;
    }
  }
  for(int num=0;num<N;num++){
    int val=0;
    for(int pos=0;pos<4;pos++){
      int mask=(num<<2)|pos;
      if(freq.count(mask)){
        val|=(1<<(2*pos))*(change?3-freq[mask]:freq[mask]);
      }else{
        val|=(1<<(2*pos))*(change?3:0);
      }
    }
    output(val);
  }
}

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