54 lines
1.1 KiB
C++
54 lines
1.1 KiB
C++
#include"stdio.h"
|
|
int main()
|
|
{
|
|
int n;
|
|
int t1[10];
|
|
int ans;
|
|
int i,j;
|
|
int a,b,t;
|
|
int num[10],k;
|
|
int hash[10];
|
|
int fac[10];
|
|
fac[0]=1;
|
|
for(i=1;i<10;i++) fac[i]=fac[i-1]*i;
|
|
t1[0]=1;
|
|
for(i=1;i<10;i++) t1[i]=9*fac[9]/fac[9-(i-1)];
|
|
while(scanf("%d",&n)!=-1)
|
|
{
|
|
if(n<=0) {printf("0\n");continue;}
|
|
if(n<10) {printf("%d\n",n-1);continue;}
|
|
k=0;
|
|
while(n)
|
|
{
|
|
num[k++]=n%10;
|
|
n/=10;
|
|
}
|
|
a=0;
|
|
b=k-1;
|
|
while(a<b)
|
|
{
|
|
t=num[a];
|
|
num[a]=num[b];
|
|
num[b]=t;
|
|
a++;
|
|
b--;
|
|
}
|
|
ans=0;
|
|
for(i=0;i<10;i++) hash[i]=1;
|
|
for(i=1;i<k;i++) ans+=t1[i];
|
|
ans+=(num[0]-1)*fac[9]/fac[10-k];
|
|
hash[num[0]]=0;
|
|
for(i=1;i<k;i++)
|
|
{
|
|
for(j=0;j<num[i];j++)
|
|
{
|
|
if(hash[j]) ans+=fac[9-i]/fac[10-k];
|
|
}
|
|
if(hash[num[i]]==0) break;
|
|
hash[num[i]]=0;
|
|
}
|
|
printf("%d\n",ans);
|
|
}
|
|
return 0;
|
|
}
|