击鼓传花

题目链接： http://exercise.acmcoder.com/online/online_judge_ques?ques_id=719&konwledgeId=136

解题思路： f[i][j]=f[i-1][j-1]+f[i-1][j+1]; f[0][1]=1;

#include <bits/stdc++.h>
using namespace std;

const int MAXN=100005;
typedef long long LL;

LL f[31][31];
int n,m;


int main()
{
#ifndef ONLINE_JUDGE
    freopen("test.txt","r",stdin);
#endif // ONLINE_JUDGE
    while(scanf("%d%d",&n,&m)!=-1)
    {
        memset(f,0LL,sizeof(f));
        f[0][1]=1LL;
        for (int i=1;i<=m;++i)
        {
            for(int j=1;j<=n;++j)
            {
                f[i][j]=(f[i-1][j-1==0?n:j-1] + f[i-1][j+1==n+1?1:j+1]);
            }
        }
        printf("%lld
",f[m][1]);
    }
    return 0;
}