Fractions to Decimals xmu1011 USACO

题目意思：

Write a program that will accept a fraction of the form N/D, where N is the numerator and D is the denominator and print the decimal representation. If the decimal representation has a repeating sequence of digits, indicate the sequence by enclosing it in brackets. For example, 1/3 = .33333333...is denoted as 0.(3), and 41/333 = 0.123123123...is denoted as 0.(123). Use xxx.0 to denote an integer. Typical conversions are:

1/3 = 0.(3)
22/5 = 4.4
1/7 = 0.(142857)
2/2 = 1.0
3/8 = 0.375
45/56 = 0.803(571428)

解题思路：除法模拟，并求出不循环位数（分成2，5的指数，取指数的最大值）

code：

#include
#include
const int size=200000;
int aa[size],t[50];
char an[size];
bool f[100001];
int main()
{
    int a,b,temp,m,t1,t2,i,j,len,l;
   while(scanf("%d%d",&a,&b)!=EOF)
   {
      if(a%b==0)
      {printf("%d.0\n",a/b);continue;}
      temp=a/b;
      if(temp==0)
      {
      t[0]=1;t[1]=0;          
      }
      else
      {
      t[0]=0;
      while(temp)
      {t[++t[0]]=temp%10;temp/=10;}
   //逆置
      for(i=1;i<=t[0]/2;i++)
      {temp=t[i];t[i]=t[t[0]-i+1];t[t[0]-i+1]=temp;}
      } 
      temp=b;t1=t2=0;
      while(temp%2==0){t1++;temp/=2;}
      while(temp%5==0){t2++;temp/=5;}
      //非循环的
      m=t1>t2?t1:t2;
      memset(f,0,sizeof(f));
      temp=a%b;len=0;
      f[temp]=1;
      while(1)
      {
         temp=temp*10;
         aa[++len]=temp/b;
         temp%=b;
   if(f[temp])break;
   f[temp]=1;
         if(temp==0)break;     
      } 
      l=0;
      for(i=1;i<=t[0];i++)
      an[++l]=t[i]+'0';
      an[++l]='.';
      for(i=1;i<=m;i++)
      an[++l]=aa[i]+'0';
      if(i<=len)
      {
      an[++l]='(';
      for(;i<=len;i++)
      an[++l]=aa[i]+'0';
      an[++l]=')';         
      } 
    
   for(i=1;i<=l;i++)
   {
    printf("%c",an[i]);
       if(i%76==0) printf("\n");
   }
   if(l%76!=0)printf("\n");
                           
   }   
}
/*
------- test 1 -------
22 5
------- test 2 -------
1 7
------- test 3 -------
100000 59
------- test 4 -------
1 100000
------- test 5 -------
3 3
------- test 6 -------
59 330
------- test 7 -------
100000 9817
------- test 8 -------
1 99991
------- test 9 -------
982 4885
*/