UVa 11809 - Floating-Point Numbers

#include <iostream>
#include <cstdio>
#include <cstring>
#include <cmath>
using namespace std;
double f[10][35];
char s[100];
double a,c;
int b;
void fuc()
{
double m=1,e;
for(int i=0;i<=9;++i)
{
m/=2;
e=1;
for(int j=0;j<=30;++j)
{
f[i][j]=log10(1-m)+log10(2)*(e-1);//用log存储
e*=2;
}
}
}
int main()
{
fuc();
while(~scanf("%s",s)&&strcmp(s,"0e0"))
{
s[17]=' ';
sscanf(s,"%lf%d",&a,&b);
c=log10(a)+b;
for(int i=0;i<=9;i++)
{
for(int j=0;j<=30;j++)
{
if(fabs(c-f[i][j])<1e-7)
{
cout<<i<<' '<<j<<endl;
break;
}
}
}
}
return 0;
}