(高精度) Octal Fractions (P1131)

注意相乘的求余等的顺序

#include<iostream>#include<algorithm>using namespace std;//freopen("C://i.txt","r",stdin);#define N 1000001int n;char s[N];int go[N];int ans[N];int main(){freopen("C://i.txt","r",stdin);int i,j,k;while (cin>>s){n=strlen(s);k=0;for (i=0;i<n;i++) if (s[i]=='.')break;for (i++;i<n;i++){go[k++]=s[i]-'0';}for (i=0;i<k;i++){ans[i]=go[i]*125;}for (i=k-1;i;i--){for (j=i;j<k;j++){ans[j]*=125;ans[j-1]+=ans[j]/1000;ans[j]%=1000;}//cout<<ans[0]<<' '<<ans[1]<<' '<<ans[2]<<endl;}while (ans[k-1]==0)k--;printf("%s [8] = 0.",s);for (i=0;i<k;i++){if (ans[i]<10){printf("00");}else if (ans[i]<100) {printf("0");}printf("%d",ans[i]);}printf(" [10]\n");}}

Octal Fractions

Time Limit: 1000MS Memory Limit: 10000KTotal Submissions: 5765 Accepted: 3162

Description

Fractions in octal (base 8) notation can be expressed exactly in decimal notation. For example, 0.75 in octal is 0.953125 (7/8 + 5/64) in decimal. All octal numbers of n digits to the right of the octal point can be expressed in no more than 3n decimal digits to the right of the decimal point.

Write a program to convert octal numerals between 0 and 1, inclusive, into equivalent decimal numerals.

Input

The input to your program will consist of octal numbers, one per line, to be converted. Each input number has the form 0.d1d2d3 ... dk, where the di are octal digits (0..7). There is no limit on k.

Output

Your output will consist of a sequence of lines of the form

0.d1d2d3 ... dk [8] = 0.D1D2D3 ... Dm [10]

where the left side is the input (in octal), and the right hand side the decimal (base 10) equivalent. There must be no trailing zeros, i.e. Dm is not equal to 0.

Sample Input

0.750.00010.01234567

Sample Output

0.75 [8] = 0.953125 [10]0.0001 [8] = 0.000244140625 [10]0.01234567 [8] = 0.020408093929290771484375 [10]