Submission #770881

#	Time	Username	Problem	Language	Result	Execution time	Memory
770881		rxlfd314	Data Transfer (IOI19_transfer)	C++17	0 / 100	96 ms	2484 KiB

transfer

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

void yeet(int N, vector<int> &v, vector<int> &source) {
	for (int j = 0; (1 << j) < N; j++) {
		v.push_back(0);
		for (int i = 0; i < N; i++) {
			if (i & 1 << j) {
				v[j] ^= source[i];
			}
		}
	}
}

vector<int> get_attachment(vector<int> source) {
	int N = source.size();
	vector<int> ret;
	yeet(N, ret, source);
	ret.push_back(0);
	for (int i = 0; i < N; i++) {
		ret.back() ^= source[i];
	}
	return ret;
}

vector<int> retrieve(vector<int> data) {
	int M = data.size();
	int N = data.size() < 255 ? 63 : 255;
	vector<int> test;
	yeet(N, test, data);
	if (test == vector<int>(data.begin()+N, data.begin()+M-1)) {
		return vector<int>(data.begin(), data.begin()+N);
	}
	bool p = 0;
	for (int i = 0; i < N; i++) {
		p ^= data[i];
	}
	if (p ^ data[M-1]) {
		for (int i = 0; i < N; i++) {
			test.clear();
			data[i] ^= 1;
			yeet(N, test, data);
			if (test == vector<int>(data.begin()+N, data.begin()+M-1)) {
				return vector<int>(data.begin(), data.begin()+N);
			}
			data[i] ^= 1;
		}
	} else {
		return vector<int>(data.begin(), data.begin()+N);
	}
}

Compilation message (stderr)

transfer.cpp: In function 'std::vector<int> retrieve(std::vector<int>)':
transfer.cpp:30:14: warning: control reaches end of non-void function [-Wreturn-type]
   30 |  vector<int> test;
      |              ^~~~

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