Submission #735867

#	Time	Username	Problem	Language	Result	Execution time	Memory
735867		rnl42	Data Transfer (IOI19_transfer)	C++14	60 / 100	7 ms	2996 KiB

transfer

#include "transfer.h"
using namespace std;

vector<int> get_attachment(vector<int> source) {
	const int N = source.size();
	//assert(__builtin_popcount(N+1) == 1);
	const int K = __lg(N+1)+1;
	vector<int> attach(K);
	for (int i = 0; i < N; i++) {
		for (int b = 0; b < K-1; b++) {
			if (((i+1) >> b) & 1) {
				attach[b] ^= source[i];
			}
		}
		attach.back() ^= source[i];
	}
	return attach;
}

vector<int> retrieve(vector<int> data) {
	int N = data.size();
	int K = __lg(N)+1;
	N -= K;

	vector<int> source(data.begin(), data.begin() + N);
	vector<int> newattach = get_attachment(source);
	int i = 0;
	for (int b = 0; b < K-1; b++) {
		if (newattach[b] != data[N+b]) {
			i |= (1<<b);
		}
	}
	i--;
	if (newattach.back() != data.back()) {
		if (i != -1) source[i] ^= 1;
	} else {
		if (i != -1) source[N+__lg(i+1)] ^= 1;
	}
	return source;
}

• Subtask 1: 60 / 60
• Subtask 2: 0 / 40