成功.cpp

算两个整数相除,可以算到小数点后无穷位.用的是数组.可以看一下

#include <iostream>
#include <fstream>
using namespace std;
int main()
{
	cout<<"Please intput two numbers,\na and b\nthis program is going to "
		"calculate a/b according to your requirement"<<endl;
	cout<<"you can set precision by n\n"<<endl;


	int a=0;
	int b=0;
	int n=0;
	int c=0;
	int next=0;
	ofstream out("Result.txt");

	cout<<"please intput a:\na=";
	cin>>a;
	out<<a;
	out<<"/";

	cout<<"please intput b:\nb=";
	cin>>b;
	out<<b<<"=";
	if(b==0)
	{
		cerr<<"error: b=0"<<endl;
		out<<"error";
		exit(1);
	}

	cout<<"please intput n:\nn=";
	cin>>n;

	if(n<0)
	{
		cerr<<"error: n<0\n";
		exit(1);
	}
	if(n==0)
	{
		cout<<a/b<<endl;
	}
	if(n>0)
	{
		c=a/b;
		cout<<c<<".";
		out<<c<<".";
		a=(a-b*c)*10;
		for(int i=1; i<n; i++)
		{
			c=a/b;
			cout<<c;
			out<<c;
			a=(a-b*c)*10;
		}
		c=a/b;
		a=(a-b*c)*10;
		next=a/b;
		cout<<c+next/5;
		out<<c+next/5;
		cout<<endl;
	}

	return 0;
}