poj 2537 Tight words dp

每次看到动态转移方程就瞬间顿悟，哎，伤不起啊~

定义dp[i][j]，第i个数字是j

dp[i][j]=dp[i-1][j-1]+dp[i-1][j]+dp[i-1][j+1];

#include <stdio.h>

int main()
{
    int k,n,i,j;
    double dp[105][15],a,b;
    while (scanf("%d%d",&k,&n)!=EOF)
    {
        if(k==0)
        {
            printf("100.00000\n");
            continue;
        }
        for (j=0;j<=10;j++)dp[1][j]=1;
        for (i=2;i<=n;i++)
        {
            for (j=0;j<=k;j++)
            {
                if(j==0)dp[i][j]=dp[i-1][j]+dp[i-1][j+1];
                else if(j==k)dp[i][j]=dp[i-1][j-1]+dp[i-1][j];
                else dp[i][j]=dp[i-1][j-1]+dp[i-1][j]+dp[i-1][j+1];
            }
        }
        a=0,b=1;
        for (j=0;j<=k;j++)a+=dp[n][j];
        for (i=1;i<=n;i++)b*=(k+1);
        printf("%.5lf\n",(a/b)*100);
    }
    return 0;
}