define S ,it is sum of all possible permutations
of a given set of digits. For example, if the digits are <1 2 3>, then six possible permutations are
<123>, <132>, <213>, <231>, <312>, <321> and the sum of them is 1332.

 

 

#include <iostream>
#include <algorithm>
#include <cstring>
#include <vector>
using namespace std;
#define int unsigned long long
 int n,S,a[50],cnt[50] ;
 const int R[] = {0,1,11,111,1111,11111,111111,
 1111111,11111111,111111111,1111111111,11111111111,111111111111};
 
 int F(int x){
 	if(x==0) return 1;
 	int r=1;
 	for(int i=2;i<=x;i++) r*=i;
 	return r;
 }
 signed main(){
 	int i;
 	while(cin>>n && n){
 		memset(cnt,0,sizeof cnt) ;
 		int ans=S=0; 
 		for(i=1;i<=n;i++){
 			cin>>a[i]; ++cnt[a[i]]; S+=a[i];
 		}
 		int k=F(n) ;
 		for(i=0;i<=9;i++) k/= F(cnt[i]);
 		
 		cout<<(k*S*R[n])/n<<endl;
 	}
 }
 
 
 

 

posted on 2023-04-17 21:04  towboat  阅读(18)  评论(0)    收藏  举报