fracdec.cpp

USACO chapter two.Useful for beginners.

/*
ID: chenkai4
PROG: fracdec
LANG: C++
*/
#include <iostream>
using namespace std;

bool hash[100001];
int chuxian[100001]={0};
int N,D;
char nums[100000];int l=0;
int main()
{
	freopen("fracdec.in","r",stdin);
	freopen("fracdec.out","w",stdout);
	scanf("%d%d",&N,&D);
	int num1=N/D;
	if(num1==0)
		nums[++l]='0';
	else
		while(num1)
		{
			nums[++l]=char(num1%10+(int)'0');
			num1/=10;
		}
	char t;
	for(int a=1;a<=l/2;a++)
	{t=nums[a];nums[a]=nums[l-a+1];nums[l-a+1]=t;}
	nums[++l]='.';
	N%=D;
	if(N==0)
		nums[++l]='0';
	else
		while(N)
		{
			if(!hash[N])
			{
				hash[N]=true;
				chuxian[N]=l+1;
				N*=10;
				nums[++l]=char(N/D+(int)'0');
				N%=D;
			}
			else
				break;
		}
	if(chuxian[N])
	{
		int ccount=0;
		for(int a=1;a<=chuxian[N]-1;a++)
		{printf("%c",nums[a]);ccount++;if(ccount%76==0){ccount=0;printf("\n");}}
		printf("(");ccount++;if(ccount%76==0){ccount=0;printf("\n");}
		for(int a=chuxian[N];a<=l;a++)
		{printf("%c",nums[a]);ccount++;if(ccount%76==0){ccount=0;printf("\n");}}
		printf(")");
	}
	else
	{
		int ccount=0;
		for(int a=1;a<=l;a++)
		{printf("%c",nums[a]);ccount++;if(ccount%76==0&&a!=l){ccount=0;printf("\n");}}
	}
	printf("\n");
	return 0;
}