poj 2537 Tight words

#include<stdio.h>#include<string.h>#include<math.h>#include<algorithm>using namespace std;int main(){    int n, k, i, j;    double dp[102][11];    while(~scanf("%d%d",&k,&n))    {        for(i=0;i<=k;i++) dp[1][i]=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]+dp[i-1][j-1];     else dp[i][j]=dp[i-1][j]+dp[i-1][j-1]+dp[i-1][j+1];        }        double s=0;        for(i=0;i<=k;i++) s+=dp[n][i];        printf("%.5fn",s*100/pow(k+1.0,n));    }    return 0;}