Submission #598752

#	Time	Username	Problem	Language	Result	Execution time	Memory
598752		farhan132	Data Transfer (IOI19_transfer)	C++17	100 / 100	205 ms	2500 KiB

transfer

#include "transfer.h"
#include <bits/stdc++.h>
 
using namespace std;
 
typedef int ll;
typedef pair<ll , ll> ii;
 
#define ff first
#define ss second
#define pb push_back
#define in insert

std::vector<int> get_attachment(std::vector<int> source) {

	ll n = source.size();
	ll lg = log2(n + 1);
	ll x = 0;
	for(auto u : source) x ^= u;
	source.pb(x);
	vector < ll > ans; ans.pb(x);
	n++;
	for(ll bit = 0; bit < lg; bit++){
		x = 0;
		for(ll i = 0; i < n; i++){
			if((i >> bit)&1) x ^= source[i];
		}
		ans.pb(x);
	}

	return ans;
}

std::vector<int> retrieve(std::vector<int> data) {

	ll n = 256;

	if(data.size() < n) n = 64;
	ll x = 0;
	for(ll i = 0; i < n - 1; i++){
		x ^= data[i];
	}
	if(data[n - 1] != x){
		ll m = data.size();
		ll cur = 0;
		for(ll j = n; j < m; j++){
			ll bit = j - n; x = 0;
			for(ll i = 0; i < n; i++){
				if((i >> bit)&1) x ^= data[i];
			}
			if(x != data[j]) cur |= (1 << bit);
		}
		data[cur] ^= 1;
	}
	while(data.size() > n-1) data.pop_back();

	return data;
}

Compilation message (stderr)

transfer.cpp: In function 'std::vector<int> retrieve(std::vector<int>)':
transfer.cpp:38:17: warning: comparison of integer expressions of different signedness: 'std::vector<int>::size_type' {aka 'long unsigned int'} and 'll' {aka 'int'} [-Wsign-compare]
   38 |  if(data.size() < n) n = 64;
      |     ~~~~~~~~~~~~^~~
transfer.cpp:55:20: warning: comparison of integer expressions of different signedness: 'std::vector<int>::size_type' {aka 'long unsigned int'} and 'll' {aka 'int'} [-Wsign-compare]
   55 |  while(data.size() > n-1) data.pop_back();
      |        ~~~~~~~~~~~~^~~~~

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