[恢]hdu 2047

2011-12-14 20:45:44

地址：http://acm.hdu.edu.cn/showproblem.php?pid=2047

题意：中文。

mark：递推，dp[i] = (dp[i-1]+dp[i-2]) * 2。要用long long

代码：

# include <stdio.h>


long long dp[45] = {1, 3} ;


int main ()
{
    int i ;
    for (i = 2 ; i <= 40 ; i++)
        dp[i] = (dp[i-1]+dp[i-2]) * 2 ;
    while (~scanf ("%d", &i))
        printf ("%I64d\n", dp[i]) ;
}