Submission #920823

#	Time	Username	Problem	Language	Result	Execution time	Memory
920823		Pannda	Parrots (IOI11_parrots)	C++17	97 / 100	9 ms	1384 KiB

encoder

#include "encoder.h"
#include "encoderlib.h"
#include <bits/stdc++.h>
using namespace std;

void encode(int n, int _a[]) {
    vector<int> a(_a, _a + n);
    for (int b = 0; b < 8; b++) {
        int cur = 0;
        for (int i = 0; i < n; i++) {
            if ((a[i] >> b & 1) != cur) {
                cur ^= 1;
                if (b < 4) {
                    send(b + 4 * i);
                } else {
                    send(b - 4 + 4 * i);
                    send(b - 4 + 4 * i);
                }
            }
        }
    }
}

decoder

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

void decode(int n, int k, int _a[]) {
    vector<int> a(_a, _a + k);

    vector<int> freq(256, 0);
    for (int x : a) {
        freq[x]++;
    }

    vector<vector<int>> change(8, vector<int>(n, 0));
    for (int x = 0; x < 256; x++) {
        if (freq[x] & 1) {
            change[x % 4][x / 4] = 1;
        }
        if (freq[x] >> 1 & 1) {
            change[x % 4 + 4][x / 4] = 1;
        }
    }

    vector<int> res(n, 0);
    for (int b = 0; b < 8; b++) {
        int cur = 0;
        for (int i = 0; i < n; i++) {
            cur ^= change[b][i];
            res[i] += cur << b;
        }
    }

    for (int x : res) {
        output(x);
    }
}

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