03:八进制小数

0.75

0.75 [8] = 0.953125 [10]

 1 #include<iostream>
 2 #include<cstdio>
 3 #include<cmath>
 4 #include<cstring>
 5 using namespace std;
 6 double ans;
 7 char a[1001];
 8 int main()
 9 {
10     double zhishu=1;
11     double fenmu;
12     gets(a);
13     int l=strlen(a);
14     for(int i=2;i<l;i++)
15     {
16         fenmu=pow(8,zhishu);
17         zhishu++;
18         ans=ans+(double)(a[i]-48)/fenmu;
19     }
20     //cout<<a<<" [8] = "<<ans<<" [10]";
21     printf("%s [8] = %.45g [10]",a,ans);
22     return 0;
23 }