进制转换.h

西电内部用的高精度库,原是保密的!!!我奉献了出来

/*----------------------进制转换---------------------------------

string change(int num,int carry):把十进制的int num转换为carry进制
                                                 的string型返回值
string change(string num, int carry1, int  carry2):把carry1进制的
                       string num转换为carry2进制的string型返回值
---------------------------------------------------------------*/
#include <fstream>
#include <string>

using namespace std;

ifstream cin("try.in");
ofstream cout("try.out");

string change(int num,int carry)
{
	string result;
	char ch;
	while(num)
	{
		ch=num%carry+'0';
		if (ch>'9') 
			ch+='a'-10-'0';
		result=ch+result;
		num/=carry;
	}
	return result;
}

string change(string num,int carry1,int carry2)
{
	int N=num.size(),i;
	int decimal=0;
	char ch;
    for(i=0;i<N;i++)
	{
		ch=num.at(i);
		if(ch<='9')
		    decimal=decimal*carry1+ch-'0';
		else decimal=decimal*carry1+ch-'a'+10;
	}
	return change(decimal,carry2);
}
/*int main()
{
	string num;
	int carry1,carry2;
	while(cin>>num>>carry1>>carry2)
	cout<<change(num,carry1,carry2)<<endl;
	return 0;
}*/