Bittijono

#include <iostream>
#include <string>
#include <random>
#include <algorithm>
#include <time.h>

using namespace std;

int bounds[27] = {1, 3, 6, 11, 19, 32, 53, 87, 142, 231, 375, 608, 985, 1595, 2582, 4179,
              6763, 10944, 17709, 28655, 46366, 75023, 121391, 196416, 317809, 514227, 832038};

int numberOfDistinct(string str)
{
	int ones = 0;
	int zeros = 0;
	long distinct = 0;
	
	for (size_t i = 0; i < str.length(); i++)
	{
		char bit = str[i];
		bool isOne = bit == '1';
		
		int newSum = 1 + distinct;
		distinct = distinct - (isOne ? ones : zeros) + newSum;
		if (isOne) ones = newSum;
		else zeros = newSum;
	}
	
	return distinct;
}

int binSizeLowerBound(int n)
{
	for (int i = 26; i != 0; i--)
	{
		int bound = bounds[i];
		if (bound < n)
		{
			return i + 1;
		}
	}
	return 1;
}

string convertToBitString(size_t value)
{
	string str(32, '0');
	
	for (size_t i = 0; i < 32; i++)
	{
		if ((1LL << i) & value)
			str[31 - i] = '1';
	}
	str = str.substr(str.find_first_not_of("0"));
	
	return str;
}


string findBitstring(string b, int n, int tries)
{
	for (int test = 0; test < tries; test++)
	{
		int maxFitness = 123456879, fitIndex = -1;
		while (true)
		{
			bool foundImprovement = false;
			for (size_t i = 0; i < b.size(); i++)
			{
				char bit = b[i];
				char rev = "01"[bit == '0'];
				b[i] = rev;
				
				int distinctSubs = numberOfDistinct(b);
				//cout << b << " : " << distinctSubs << "\n";
				
				int fitness = abs(distinctSubs - n);
				if (fitness == 0)
				{
					// Solution found.
					return b;
				}
				if (fitness < maxFitness)
				{
					maxFitness = fitness;
					fitIndex = (int)i;
					foundImprovement = true;
				}
				
				b[i] = bit;
			}
			
			if (foundImprovement) b[fitIndex] = "01"[b[fitIndex] == '0'];
			else
			{
				//cout << "No improvement found :-( shuffling\n";
				size_t len = b.size();
				size_t ones = len - (rand() % len);
				for (size_t i = 0; i < len; i++)
				{
					b[i] = "01"[i < ones];
				}
				random_shuffle(b.begin(), b.end());
				break;
			}
		}
	}
	return "fail";
}


int main()
{
	ios_base::sync_with_stdio(0);
	cin.tie(0);
	srand(time(NULL));
	
	/*
	long n;
	cin >> n;*/
	//int base = (int)log2(n);
	
	//cout << base << "\n";
	int n;
	cin >> n;
	bool found = false;
	string maxChain = "1010101010101010101010101010";
	
	int len = binSizeLowerBound(n);
	int low = len + 1;
	int high = len + 2;
	
	for (int i = 0; i < 27; i++)
		if (bounds[i] == n) found = true;
		
	if (found) cout << maxChain.substr(0, low);
	else
	{
		string p1 = maxChain.substr(0, low);
		string p2 = maxChain.substr(0, high);
		
		string res1 = findBitstring(p1, n, 1000);
		if (res1 == "fail")
		{
			res1 = findBitstring(p2, n, 1000);
		}
		
		cout << res1;
	}
	
	
	//cout << findBitstring("010101010100000001010101010", 832038, 1000);

	
	//cout << m << "\n";
	//cout << numberOfDistinct(str) << "\n";
	
	return 0;
}

Test 1

Group: 1

Verdict: WRONG ANSWER

Test 2

Group: 1

Verdict: ACCEPTED

Test 3

Group: 1

Verdict: ACCEPTED

Test 4

Group: 1

Verdict: ACCEPTED

Test 5

Group: 1

Verdict: ACCEPTED

Test 6

Group: 1

Verdict: ACCEPTED

Test 7

Group: 1

Verdict: ACCEPTED

Test 8

Group: 1

Verdict: ACCEPTED

Test 9

Group: 1

Verdict: ACCEPTED

Test 10

Group: 1

Verdict: ACCEPTED

Test 11

Group: 2

Verdict: ACCEPTED

Test 12

Group: 2

Verdict: ACCEPTED

Test 13

Group: 2

Verdict: ACCEPTED

Test 14

Group: 2

Verdict: ACCEPTED

Test 15

Group: 2

Verdict: ACCEPTED

Test 16

Group: 2

Verdict: ACCEPTED

Test 17

Group: 2

Verdict: ACCEPTED

Test 18

Group: 2

Verdict: ACCEPTED

Test 19

Group: 2

Verdict: ACCEPTED

Test 20

Group: 2

Verdict: ACCEPTED

Test 21

Group: 3

Verdict: ACCEPTED

Test 22

Group: 3

Verdict: ACCEPTED

Test 23

Group: 3

Verdict: ACCEPTED

Test 24

Group: 3

Verdict: ACCEPTED

Test 25

Group: 3

Verdict: ACCEPTED

Test 26

Group: 3

Verdict: ACCEPTED

Test 27

Group: 3

Verdict: ACCEPTED

Test 28

Group: 3

Verdict: ACCEPTED

Test 29

Group: 3

Verdict: ACCEPTED

Test 30

Group: 3

Verdict: ACCEPTED

Test 31

Group: 4

Verdict: WRONG ANSWER

Test 32

Group: 4

Verdict: WRONG ANSWER

Test 33

Group: 4

Verdict: WRONG ANSWER

Test 34

Group: 4

Verdict: WRONG ANSWER

Test 35

Group: 4

Verdict: WRONG ANSWER

Test 36

Group: 4

Verdict: WRONG ANSWER

Test 37

Group: 4

Verdict: WRONG ANSWER

Test 38

Group: 4

Verdict: ACCEPTED

Test 39

Group: 4

Verdict: WRONG ANSWER

Test 40

Group: 4

Verdict: ACCEPTED