Submission #896507

#	Time	Username	Problem	Language	Result	Execution time	Memory
896507		anton	Parrots (IOI11_parrots)	C++17	97 / 100	8 ms	1816 KiB

encoder

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

using namespace std;
#define ll long long


void encode(int N, int M[])
{
    vector<int> mes(N);
    vector<int> tb;
    for(int i = 0; i<256; i++){
        if(bitset<8>(i).count() ==4){
            tb.push_back(i);
        }
    }
    for(int i =0; i<N; i++){
        mes[i] = M[i]^(tb[i%tb.size()]);
    }
    if(N>32){
        
        int id = 0;
        for(int i=0; i<N; i++){
            for(int j = 0; j<8; j+=2){
                int oc = (mes[i] & (3<<j))>>j;
                for(int k = 0; k<oc; k++){
                    send(id);
                }
                id++;
            }
        }
    }
    else{
        int id = 0;
        for(int i=0; i<N; i++){
            for(int j = 0; j<8; j++){
                if((mes[i] & (1<<j))!=0){
                    send(id);
                }
                id++;
            }

        }
    }

}

decoder

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

using namespace std;

void decode(int N, int L, int X[])
{
    
    vector<int> res(N);
    if(N<=32){
                vector<int> v(L);

        for(int i = 0; i<L; i++){
            v[i] = X[i];
        }
        sort(v.begin(), v.end());
        bool swaping = false;
        for(int i = 0; i<L; i++){
            if(i>0 && v[i]==v[i-1]){
            swaping = true;
            }
            res[v[i]/8]^=(1<<(v[i]%8));
        }
        for(auto e: res){
            //cout<<bitset<8>(e)<<endl;
        }

        if(swaping){
            //cout<<"swapping"<<endl;
            for(int i = 0; i<N; i++){
            res[i] ^= (1<<8)-1;
            }
        }
    }
    else{
        ////cout<<"L "<<L<<endl;
        vector<int> v(L);

        for(int i = 0; i<L; i++){
            v[i] = X[i];
        }
        sort(v.begin(), v.end());
        reverse(v.begin(), v.end());
        for(int pos = 0; pos<N*4; pos++){
            int oc= 0;
            while(v.size()>0 && v.back() == pos){
                oc++;
                v.pop_back();
            }
            //cout<<bitset<8>(oc<<((2*pos)%8));
            res[pos/4] ^= (oc<<((2*pos)%8));
        }

    }
    vector<int> tb;
    for(int i = 0; i<256; i++){
        if(bitset<8>(i).count() ==4){
            tb.push_back(i);
        }
    }

    for(int i = 0; i<N; i++){
        res[i] = res[i]^tb[i%tb.size()];
    }

    for(auto e: res){
        output(e);
    }
}

Compilation message (stderr)

decoder.cpp: In function 'void decode(int, int, int*)':
decoder.cpp:25:18: warning: unused variable 'e' [-Wunused-variable]
   25 |         for(auto e: res){
      |                  ^

• Subtask 1: 17 / 17
• Subtask 2: 17 / 17
• Subtask 3: 18 / 18
• Subtask 4: 29 / 29
• Subtask 5: 16 / 19