这道题的银行利率300%不算高利贷吗

#include<bits/stdc++.h>
using namespace std;
int main()
{
	double a,b,c;
	cin>>a>>b>>c;
	double l=0,r=4;
	while(r-l>0.0001)
	{
		double mid=l+(r-l)/2.0;
		double x=a;
		for(int i=1;i<=c;i++)
		{
			x=x-b+x*mid;
		}
		if(x>0.0001)r=mid-0.00001;
		else l=mid+0.00001;
	}
	printf("%.1lf",l*100);
}