C :

int main(int argc, char* argv[])
{int i,n,k;
double sum,sum1;
while(~scanf("%d%d",&n,&k))
{ sum=200;sum1=n;
for(i=0;i<20;i++)
{
	if(sum1>=sum)break;
sum=sum*(1+k*1.0/100);
sum1+=n;

}
if(i>19)printf("Impossible\n");
else printf("%d\n",i+1);

}
	return 0;
}

C++ :

#include <iostream>
using namespace std;

int main()
{
	int N,K;
	while(cin>>N>>K)
	{
		float price = 200;
		float earn  = N;
		int year =1;
		while( earn <price )
		{	//每年一次循环 
			if(year>20)
			{	
				cout<<"Impossible"<<endl;
				break;
			}
			//cout<<"year: "<<year<<"earn:"<<earn<<"price"<<price<<endl;
			earn += N;//总收入增加 
			price = price*(1.0+(float)K/100);//房价增加 
			year++;
		}
		if(year<=20)
			cout<<year<<endl;
	}
	return 0;
}

Java :

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner shuru = new Scanner(System.in);
        while(shuru.hasNext())
        {
                int N = shuru.nextInt();
                int K = shuru.nextInt();
                int flag = 0;
                for (int i = 0; i<20; i++) {
                    if (N*(i+1) >= 200 * Math.pow(1.0+K/100.0,i)) {
                        System.out.println(i+1);
                        flag = 1;
                        break;
                    }
                }
                if (flag == 0)
                    System.out.printf("Impossible\n");
        }
    }
}