整数转换成罗马数字

给定一个整数num，( 1<=num<=3999)，将整数转换成罗马数字。

如1,2,3,4,5对应的罗马数字分别位I，II，III，IV，V等。

格式：

第一行输入一个整数，接下来输出对应的罗马数字。

提示：

罗马数字的常识见此链接，对做题有帮助哦～尤其是表示方法。

http://baike.baidu.com/link?url=injU8M4bAoc2zRZQ1GtgrfvuzCJO9PLnq6fpQGJLenakbzo-rS8p-qsYHR_81-aN

样例输入

123

样例输出

CXXIII

#include
#include
#include
#include
#include
using namespace std;
string a[4][9]={
      "I","II","III","IV","V","VI","VII","VIII","IX",
      "X","XX","XXX","XL","L","LX","LXX","LXXX","XC",
      "C","CC","CCC","CD","D","DC","DCC","DCCC","CM",
      "M","MM","MMM"};

int main()
{
    int n;
    while(cin>>n)
    {
        int k,b,d,c;
         k=n/1000, n%=1000;
         b=n/100,n%=100;
         d=n/10 ,n%=10;
         c=n;
        if(k-1>=0)
        {
            cout<3][k-1];
        }
        if(b-1>=0)
        {
           cout<2][b-1];
        }
        if(d-1>=0)
        {
            cout<1][d-1];
        }
        if(c-1>=0)
        {
            cout<0][c-1];
        }
        cout<return 0;
}