Project Euler #112: Bouncy Numbers

Working from left-to-right if no digit is exceeded by the digit to its left it is called an increasing number; for example, 134468.

Similarly if no digit is exceeded by the digit to its right it is called a decreasing number; for example, 66420.

We shall call a positive integer that is neither increasing nor decreasing a "bouncy" number; for example, 155349.

Clearly there cannot be any bouncy numbers below one-hundred, but just over half of the numbers below one-thousand (525) are bouncy. In fact, the least number for which the proportion of bouncy numbers first reaches 50% is 538.

Surprisingly, bouncy numbers become more and more common and by the time we reach 21780 the proportion of bouncy numbers is equal to 90%.

Find the least number for which the proportion of bouncy numbers is exactly 99%.

#include <iostream>
#include <vector>
#include <algorithm>

bool bouncyCheck(int passedNumb);

int main(void)
{
	double percentCheck = 0;
	unsigned long long bouncy = 0, unbouncy = 99; // all two digit are unbouncy, so set to 99


	for(int i = 100; percentCheck != 99; i++)
	{
		if(bouncyCheck(i)) // if determiend to be bouncy
		{
			bouncy++;
		}
		else // it is unbouncy
		{
			unbouncy++;
		}

		percentCheck = ( (100.0 / (bouncy + unbouncy)) * bouncy); // calculate percentage
	}

	std::cout << "The answer is" << bouncy + unbouncy; 
}

bool bouncyCheck(int passedNumb)
{
	std::vector<int> digBuff, sortBuff;

	while(passedNumb) // separate into vector of digits
	{
		digBuff.insert(digBuff.begin(), passedNumb % 10);
		passedNumb /= 10;
	}

	sortBuff = digBuff; // copy

	std::sort(sortBuff.begin(), sortBuff.end()); // sort to check for ascending/descending

	if(sortBuff == digBuff) // if equal, we know it is not bouncy
	{
		return false;
	}

	std::reverse(sortBuff.begin(), sortBuff.end());

	if(sortBuff == digBuff) // if equal, we know it is not bouncy
	{
		return false;
	}

	return true;
}