Submission #742845

#	Time	Username	Problem	Language	Result	Execution time	Memory
742845		nguyentunglam	Data Transfer (IOI19_transfer)	C++17	100 / 100	513 ms	2516 KiB

transfer

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

void up(int &pos) {
    pos++;
    while (__builtin_popcount(pos) == 1) pos++;
}

std::vector<int> get_attachment(std::vector<int> source) {
    int T = source.size() <= 63 ? 7 : 9;
    vector<int> ret(T);
    int pos = 0, timer = 0;
    for(int &val : source) {
        up(pos);
        for(int j = 0; j < T; j++) if (pos >> j & 1)  ret[j] ^= val;
    }
//    for(int &j : ret) cout << j; cout << endl;
    return ret;
}

std::vector<int> retrieve(std::vector<int> data) {
    int T = data.size() - 7 <= 63 ? 7 : 9;
    int n = data.size() - T;
    vector<int> ret;
    int pos = 0;
    for(int i = 0; i < n; i++) {
        up(pos);
        for(int j = 0; j < T; j++) if (pos >> j & 1) data[j + n] ^= data[i];
    }
    int wrong = 0;
    pos = 0;
    for(int j = 0; j < T; j++) if (data[j + n]) wrong |= (1 << j);
    for(int i = 0; i < n; i++) {
        up(pos);
        if (pos == wrong) data[i] ^= 1;
        ret.push_back(data[i]);
    }
    return ret;
}

Compilation message (stderr)

transfer.cpp: In function 'std::vector<int> get_attachment(std::vector<int>)':
transfer.cpp:13:18: warning: unused variable 'timer' [-Wunused-variable]
   13 |     int pos = 0, timer = 0;
      |                  ^~~~~

• Subtask 1: 60 / 60
• Subtask 2: 40 / 40