Submission #39301

#	Time	Username	Problem	Language	Result	Execution time	Memory
39301		tjd229	Parrots (IOI11_parrots)	C++11	98 / 100	17 ms	2384 KiB

encoder

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

void encode(int N, int M[])
{
	int i,j;
	int ix = 0;
	int bit8 = 1 << 7;
	int bit;
	int n = N < 32 ? N : 32;
	int M1[15 * 64];
	int M2[15 * 64];
	int p1 = 0;
	int p2 = 0;
	for (i = 0; i < n; i++){
		bit = bit8;
		for (j = 0; j < 8; j++, bit >>= 1, ix++)
			if (bit&M[i])
				M1[p1++] = ix;
			else
				M2[p2++] = ix;
	}
	for (ix=0; i < N; i++){
		bit = bit8;
		for (j = 0; j < 8; j++, bit >>= 1, ix++)
			if (bit&M[i]){
				M1[p1++] = ix;
				M1[p1++] = ix;
			}
			else{
				M2[p2++] = ix;
				M2[p2++] = ix;
			}
	}
	for (i = 0; i < 4;i++)
		M2[p2++]=0;
	if (p2 < p1)
		for (i = 0; i < p2; i++) send(M2[i]);
	else
		for (i = 0; i < p1; i++) send(M1[i]);
}

decoder

#include "decoder.h"
#include "decoderlib.h"

void decode(int N, int L, int X[])
{
	int i,j;
	int cnt[256] = { 0 };
	int recover;
	int n = N < 32 ? N : 32;
	int c = 0;
	for (i = 0; i < L; i++)
		cnt[X[i]]++;
	
	if (cnt[0] & 4)
		c = 255;
	for (i = 0,n*=8; i < n;){
		recover = 0;
		for (j = 0; j < 8; j++, i++){
			recover <<= 1;
			if (cnt[i]&1)
				recover += 1;
		}		
		output(recover^c);
	}
	for (N *= 8; i < N;){
		recover = 0;
		for (j = 0; j < 8; j++, i++){
			recover <<= 1;
			if (cnt[i-256] & 2)
				recover += 1;
			
		}
		output(recover^c);
	}
}

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