【USACO 2.2】Preface Numbering (找规律)

/*
TASK: preface
LANG: C++
 */
#include<cstdio>
int n;
char s[10]="IVXLCDM";
int num[15]={0,1,2,3,1,0,1,2,3,1,0};
int ans[10];
void get(int n){
    int i=0;
    while(n){
        int t=n%10;
        n/=10;
        ans[i]+=num[t];
        if(t>=4&&t<9)ans[i+1]++;
        if(t==9)ans[i+2]++;
        i+=2;
    }
}
int main(){
    freopen("preface.in","r",stdin);
    freopen("preface.out","w",stdout);
    scanf("%d",&n);
//    get(n);
    for(int i=1;i<=n;i++)    
        get(i);
    for(int i=0;s[i];i++)if(ans[i])
        printf("%c %d\n",s[i],ans[i]);
}