src/projecteuler/112.c


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int isbouncy(unsigned long n)
{
	char increasing=1, decreasing=1;
	char lastdigit = n % 10;
	n /= 10;

	while(n > 0)
	{
		char digit = n % 10;
		if(digit > lastdigit)
			increasing = 0;
		else if(digit < lastdigit)
			decreasing = 0;

		if(increasing == 0 && decreasing == 0)
			return 1;

		lastdigit = digit;
		n /= 10;
	}
	return 0;
}

int main(void)
{
	unsigned long n = 100;
	unsigned long bouncycount = 0;
	double ratio;

	while(1)
	{
		if(isbouncy(++n))
			bouncycount++;

		ratio = (double)bouncycount/n;
		if(ratio == 0.99)
			break;

	}
	printf("%ld\n", n);

	return 0;
}