Submission #143837

#	Submission time	Handle	Problem	Language	Result	Execution time	Memory
143837	2019-08-15T09:56:03 Z	SpeedOfMagic	Data Transfer (IOI19_transfer)	C++17	100 / 100	161 ms	2652 KB

transfer

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

vector<int> get_attachment(vector<int> source) {
	int x = 0;
	vector<int> res;
	
	for (int i = 0; i < source.size(); i++)
		x ^= (i + 1) * source[i];
	
	int lim = (source.size() == 63) ? 6 : 8;
	int X = 0;
	for (int i = 0; i < lim; i++) {
		int d = (x & (1 << i)) != 0;
		res.push_back(d);
		X ^= d;
	}
	
	res.push_back(X);
	return res;
}

vector<int> retrieve(vector<int> data) {
	//for (int i = 0; i < data.size(); i++) cout << data[i]; cout << endl;
	int st;
	int len;
	if (data.size() == 70) {
		st = 63;
		len = 6;
	} else {
		st = 255;
		len = 8;
	}
	
	int x = 0;
	int X = 0;
	for (int i = st; i < st + len; i++) {
		x += (1 << (i - st)) * data[i];
		X ^= data[i];
	}
	
	int rx = 0;
	for (int i = 0; i < st; i++)
		rx ^= (i + 1) * data[i];
	
	vector<int> ans;
	if (x != rx) {
		if (X != data.back()) { //problem with xor
			for (int i = 0; i < st; i++)
				ans.push_back(data[i]);
		} else { //problem with the main part
			for (int i = 0; i < st; i++) {
				if ((rx ^ (i + 1)) == x)
					ans.push_back(1 - data[i]);
				else
					ans.push_back(data[i]);
			}
		}
	} else //problem with the last bit, or there's no problem
		for (int i = 0; i < st; i++)
			ans.push_back(data[i]);
	//for (int i : ans) cout << i; cout << endl;
	
	return ans;
}

Compilation message

transfer.cpp: In function 'std::vector<int> get_attachment(std::vector<int>)':
transfer.cpp:9:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for (int i = 0; i < source.size(); i++)
                  ~~^~~~~~~~~~~~~~~

Subtask #1

60.0 / 60.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	8 ms	976 KB	Output is correct
2	Correct	8 ms	1024 KB	Output is correct
3	Correct	8 ms	1132 KB	Output is correct
4	Correct	8 ms	1004 KB	Output is correct
5	Correct	8 ms	1016 KB	Output is correct
6	Correct	8 ms	1016 KB	Output is correct
7	Correct	8 ms	1016 KB	Output is correct
8	Correct	8 ms	888 KB	Output is correct
9	Correct	8 ms	1016 KB	Output is correct
10	Correct	8 ms	1144 KB	Output is correct
11	Correct	8 ms	896 KB	Output is correct
12	Correct	8 ms	1100 KB	Output is correct
13	Correct	8 ms	972 KB	Output is correct
14	Correct	9 ms	888 KB	Output is correct
15	Correct	8 ms	976 KB	Output is correct
16	Correct	8 ms	1028 KB	Output is correct
17	Correct	8 ms	904 KB	Output is correct

Subtask #2

40.0 / 40.0

#	Verdict	Execution time	Memory	Grader output
1	Correct	154 ms	2612 KB	Output is correct
2	Correct	154 ms	2612 KB	Output is correct
3	Correct	153 ms	2604 KB	Output is correct
4	Correct	155 ms	2652 KB	Output is correct
5	Correct	156 ms	2612 KB	Output is correct
6	Correct	154 ms	2604 KB	Output is correct
7	Correct	158 ms	2604 KB	Output is correct
8	Correct	158 ms	2604 KB	Output is correct
9	Correct	155 ms	2640 KB	Output is correct
10	Correct	153 ms	2484 KB	Output is correct
11	Correct	153 ms	2628 KB	Output is correct
12	Correct	158 ms	2628 KB	Output is correct
13	Correct	154 ms	2604 KB	Output is correct
14	Correct	156 ms	2600 KB	Output is correct
15	Correct	155 ms	2620 KB	Output is correct
16	Correct	153 ms	2608 KB	Output is correct
17	Correct	154 ms	2608 KB	Output is correct
18	Correct	154 ms	2624 KB	Output is correct
19	Correct	161 ms	2624 KB	Output is correct