SECTION 2.2 Preface Numbering

/*ID: zhangzz4PROG: prefaceLANG: C++*/#include<stdio.h>#include<string.h>const char L[]={"IVXLCDM"};int f[8];void add(int x){ int ten=1,b=0; for(int i=0;i<4;i++,b+=2) { int d=x/ten%10; ten*=10; int f1=0,f2=0; switch(d) { case 1:f1++;break; case 2:f1+=2;break; case 3:f1+=3;break; case 4:f1++,f2++;break; case 5:f2++;break; case 6:f1++,f2++;break; case 7:f2++,f1+=2;break; case 8:f2++,f1+=3;break; case 9:f[b+2]++,f1++;break; } f[b]+=f1,f[b+1]+=f2; }}int main(){ freopen("preface.in","r",stdin); freopen("preface.out","w",stdout); int n; scanf("%d",&n); for(int i=1;i<=n;i++) add(i); for(int i=0;i<7;i++) if(f[i]) printf("%c %d/n",L[i],f[i]);}