HDOJ 3482 Good Serial Inc.

描述不清。。。没有意义的水题。。。。

Good Serial Inc.

Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)
Total Submission(s): 605    Accepted Submission(s): 244

Problem Description

Good Serial Inc. (GSI) produces integer sequences with length N, in which every element is an integer in range [1, M].
They call a sequence S is good if the sequence has the following property: for every substring of S with length M, i.e., S[i -> i+m-1], all the elements in the substring are the same or all the elements are distinct(different from each other).
The company GIS is designed to produce good sequences. But how many different good sequences are there? Since the answer will be very large, just output the result after module 987654321.

 

Input

There are several cases. For each case, there is a line with two integers N, and M ( 1 ≤ N ≤ 1000000, 1 ≤ M ≤ 1000000 ).
The input ends up with two negative numbers, which should not be processed as a case.

 

Output

Print the number of different good sequences module 987654321 in a line for each case.

 

Sample Input

   
   
   
   

    
    
    
    4 4
3 5
-1 -1
   
   
   
   

 

Sample Output

   
   
   
   

    
    
    
    28
125
   
   
   
   

 

Source

2010 ACM-ICPC Multi-University Training Contest（5）——Host by BJTU

 

#include <iostream>
#include <cstdio>
#include <cstring>
#include <algorithm>

using namespace std;

typedef long long int LL;
const LL mod=987654321;

int main()
{
    int n,m;
while(scanf("%d%d",&n,&m)!=EOF)
{
    if(n==-1&&m==-1) break;
    LL ans=m,jie=1;

    if(m<=2||n<m)
    {
        ans=0;
        for(int i=0;i<n;i++)
        {
            jie=(jie*m)%mod;
        }
        ans=jie;
    }
    else if(n>=m)
    {
        for(int i=1;i<=m;i++)
        {
            jie=(jie*i)%mod;
        }
        ans=(ans+jie)%mod;
    }
    printf("%I64d\n",ans);
}
    return 0;
}