Submission #829860

#	Time	Username	Problem	Language	Result	Execution time	Memory
829860		vqpahmad	Data Transfer (IOI19_transfer)	C++14	100 / 100	235 ms	2500 KiB

transfer

#include<bits/stdc++.h>
using namespace std;
#define ll long long
#define pii pair<int,int>
#define F first
#define S second
#define endl '\n'
#define pb push_back
#define sz(a) (int)a.size()
#define all(a) a.begin(),a.end()
const int mod = 1e9 + 7;
const int N = 1e6 + 15;
const ll inf = 1e18;

#include "transfer.h"

vector<int> get_attachment(vector<int> source) {
	int n = sz(source);
	int B;
	if (n<=63){
		B = 7;
	}
	else B = 9;

	vector<int> a(B);
	for (int i=1;i<=n;i++){
		for (int b=0;b<B-1;b++){
			if ((i>>b)&1) a[b] ^= source[i-1];
		}
	}
	for (int i=0;i<B-1;i++){
		a[B-1] ^= a[i];
	}
	return a;
}

vector<int> retrieve(vector<int> data) {
	int n = sz(data);
	int B;
	if (n<=63+7){
		B = 7;
	}
	else B = 9;
	n -= B;
	int ans = 0;
	bool ok = 1;
	int cur = 0;
	for (int i=n;i<n+B-1;i++){
		cur ^= data[i];
	}
	ok &= data.back()==cur;
	vector<int> c(B-1);
	for (int i=1;i<=n;i++){
		for (int b=0;b<B-1;b++){
			if ((i>>b)&1) c[b] ^= data[i-1];
		}
	}
	for (int i=n;i<n+B-1;i++){
		if (data[i] != c[i-n]) ans |= (1<<(i-n));
	}
	vector<int> fin_ans(n);
	if (ans==0 or !ok){
		for (int i=0;i<n;i++){
			fin_ans[i] = data[i];
		}
	}
	else {
		for (int i=0;i<n;i++){
			if (ans==i+1) fin_ans[i] = 1^data[i];
			else fin_ans[i] = data[i];
		}
	}
	return fin_ans;
}

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