Submission #902872

#	Time	Username	Problem	Language	Result	Execution time	Memory
902872		heavylightdecomp	Parrots (IOI11_parrots)	C++14	17 / 100	11 ms	1968 KiB

encoder

#include "encoder.h"
#include "encoderlib.h"
#include<bits/stdc++.h>
using namespace std;
#define vt vector
#define pb push_back
#define X first
#define Y second
using pii = pair<int,int>;
#define debug(x) do\
{auto _x=x; cerr<<#x<<" = "<<_x<<'\n';}while(0);
#define f0r(i,a,b) for(auto i=(a);i<(b);i++)
#define r0f(i,a,b) for(auto i=(a);i>=(b);i--)
#define all(x) (x).begin(), (x).end()
#define sz(x) ((int)(x).size())
// Bash out all the bits???
// Encode the first 2 position bits in the number of send times
// Encode the next 3 in the actual number [7,6,5]
// Encode the head/tail bit in actual number [4]
// use bit tricks to find head and tail
// Potential bug: zeroes in times
void mysend(int a, int times) {
    f0r(i,0,times) send(a);
}
void encode(int N, int M[]) {
    f0r(pos,0,N) {
        int times = (pos >> 3) + 1;
        int body = ((pos & ((1 << 3) - 1)) << 5);
        int head = M[pos] >> 4;
        int tail = M[pos] & ((1 << 4) - 1);
        mysend(body | (1 << 4) | head, times);
        mysend(body | tail, times);
    }
}

decoder

#include "decoder.h"
#include "decoderlib.h"
#include<bits/stdc++.h>
using namespace std;
#define vt vector
#define pb push_back
#define X first
#define Y second
using pii = pair<int,int>;
#define debug(x) do\
{auto _x=x; cerr<<#x<<" = "<<_x<<'\n';}while(0);
#define f0r(i,a,b) for(auto i=(a);i<(b);i++)
#define r0f(i,a,b) for(auto i=(a);i>=(b);i--)
#define all(x) (x).begin(), (x).end()
#define sz(x) ((int)(x).size())
//potential bug: confusion between N and L
void decode(int d_sz, int N, int xs[]) {
    vt<int> freq (255);
    vt<int> ans (d_sz);
    f0r(i,0,N) {
        freq[xs[i]]++;
    }
    f0r(a,0,255) if(freq[a]) { //BUG : need to check if 0 times
        int times = freq[a] - 1; //First 2 position bits
        int nt = a >> 5; //Next 3 position bits
        bool is_heads = !!(a & (1 << 4));
        int block = a & ((1 << 4) - 1);
        int where = (times << 3) + nt;
        if(is_heads) {
            ans[where] += block << 4;
        } else {
            ans[where] += block;
        }
    }
    f0r(i,0,d_sz) {
        output(ans[i]);
    }
}

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