Num romanos

#include<iostream>
#include<stdio.h>
#include<stdlib.h>
#include<string.h>
#include<string>
using namespace std;

int main()
{
    char nr1[15], nr2[15], op,rnr1[15];
    int nd1=0, nd2=0, tnr1=0, tnr2=0,i=0,j=0;

    cout<<"Digite um numero romano: "<<endl;
    cin>>nr1;

    tnr1=strlen(nr1);

    for(i=1;i<=tnr1;i++)
    {
        if(strcmp(nr1,"I")==0)
        {
            nd1=nd1+1;
        }
        if(strcmp(nr1,"V")==0)
        {
            nd1=nd1+5;
        }
        if(strcmp(nr1,"X")==0)
        {
            nd1=nd1+10;
        }

        if(strcmp(nr1,"L")==0)
        {
            nd1=nd1+50;
        }
        if(strcmp(nr1,"C")==0)
        {
            nd1=nd1+100;
        }
        if(strcmp(nr1,"D")==0)
        {
            nd1=nd1+500;
        }
        if(strcmp(nr1,"M")==0)
        {
            nd1=nd1+1000;
        }
    }
    cout<<"valor final "<<nd1<<endl;
}