poj 1790 Base Numbers

poj 1790 Base Numbers

#include <stdio.h>#include <string.h>char st[40],num[40],*base;int lenb;long long f[40],ans;int minx(int x,int y){return (x<y)?x:y;}int cmp(int l,int r){ int i; for (i=l; i<r; ++i)  num[i-l]=st[i]; num[r-l]=''; return strcmp(num,base);}void count(int x){ int i,j,k; for (i=x-1; i>=0; --i)  if (st[i]!='0') {   k=minx(i+lenb,x);   for (j=i+1; j<=k; ++j)    if (j-i<lenb || j-i==lenb && cmp(i,j)<0)     f[i]+=f[j];  } else   f[i]+=f[i+1];}int main(){ int i,j; while (scanf("%s",st),st[0]!='#') {  if (st[0]=='0') {   printf((st[1]=='' || st[1]=='0' || st[1]=='1' && st[2]=='')?"The pre %s is invalid.n":"The pre %s can represent 1 numbers.n",st);   continue;  }  ans=0;  for (i=(int)strlen(st)-1,j=1; i; --i,++j)   if (st[i]!='0') {    memset(f,0,sizeof(f));    f[i]=1;    base=st+i;    lenb=j;    count(i);    ans+=f[0];   }  (ans)?printf("The pre %s can represent %lld numbers.n",st,ans):printf("The pre %s is invalid.n",st); } return 0;}