SGU 456 Annuity Payment Scheme

 1 /*************************************************************************
 2     > File Name: code/2015summer/#5/D.cpp
 3     > Author: 111qqz
 4     > Email: rkz2013@126.com 
 5     > Created Time: 2015年07月30日 星期四 13时17分26秒
 6  ************************************************************************/
 7 
 8 #include<iostream>
 9 #include<iomanip>
10 #include<cstdio>
11 #include<algorithm>
12 #include<cmath>
13 #include<cstring>
14 #include<string>
15 #include<map>
16 #include<set>
17 #include<queue>
18 #include<vector>
19 #include<stack>
20 #define y0 abc111qqz
21 #define y1 hust111qqz
22 #define yn hez111qqz
23 #define j1 cute111qqz
24 #define tm crazy111qqz
25 #define lr dying111qqz
26 using namespace std;
27 #define REP(i, n) for (int i=0;i<int(n);++i)  
28 typedef long long LL;
29 typedef unsigned long long ULL;
30 const int inf = 0x7fffffff;
31 int s,m,p;
32 double ans;
33 
34 double cal(double x,int n)
35 {
36     double res = 1.0;
37     for ( int i = 1 ; i <= n ; i++ )
38     {
39     res = res * x;
40     }
41   //  cout<<"res:"<<res<<endl;
42     return res;
43 }
44 int main()
45 {
46     cin>>s>>m>>p;
47     double sum = 0;
48     double per = p*1.0/100+1;
49     for ( int i = 1 ; i <= m;  i++ )
50     {
51     sum=sum+1.0/cal(per,i);
52 //    cout<<"sum:"<<sum<<endl;
53     }
54  //   cout<<sum<<endl;
55     cout<<fixed<<setprecision(5)<<s*1.0/sum<<endl;
56   
57     return 0;
58 }