Usaco Training 2.4.5 Fractions to decimals

Well... With a theorem, for a simplest fraction n/d,d= (2^x) * (5^y) *m,m≠1, then its loop length is the smallest L that makes the 10^l mod m==1, the non-cyclic length is max (x, y)

Then the question is nothing.

76 characters a line-break comparison pit, I used the stringstream ...

1#include <iostream>2#include <sstream>3#include <cstdio>4#include <iomanip>5#include <algorithm>6#include <string>7 using namespacestd;8typedefLong LongLL;9 strings;Ten intPow_mod (intAintBintMoD) One { ALLBase=a,ans=1; -      while(b) -     { the         if(b&1) ans=ans*Base%MoD; -         Base=Base*Base%MoD; -b>>=1; -     } +     return(int) ans; - } + intgcdintAintb) A { at     returnb==0? A:GCD (b,a%b); - } - intX,y,m,n,d;//n/d d=2^x * 5^y * M - intMain () - { -Freopen ("fracdec.in","R", stdin); inFreopen ("Fracdec.out","W", stdout); - StringStream SS; toCin>>n>>D; +     intg=gcd (n,d); -N/=g;d/=G; them=D; *      while(m>1&& (m&1)==0) m>>=1,++x; $      while(m>1&& (m%5)==0) m/=5,++y;Panax Notoginseng     if(m==1)  -     { the         if(n%d==0) ss<<n/d<<". 0"; +         ElseSs<<setprecision (max (x, y)) <<setiosflags (iOS::fixed) << (Double) n/(Double) D; A     } the     Else +     { -         inti; $          for(i=1;; ++i)if(Pow_mod (Ten, i,m) = =1) Break; $         //printf ("%d\n", I); -ss<<n/d<<'.'; -n%=D; the          for(intj=0; J<max (x, y) +i;++j) -         {Wuyi             if(J==max (x, y)) ss<<'('; then*=Ten; -ss<<n/D; Wun%=D; -         } Aboutss<<')'; $     } -Ss>>s; -     intsz=s.length (); -      for(intI=0; i<sz;++i) A     { +         if(i% the==0&& i!=0) Putchar (Ten); the Putchar (S[i]); -     } $Putchar (Ten); the     return 0; the}

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Usaco Training 2.4.5 Fractions to decimals