HDU 2045 - 不容易系列之(3)—— LELE的RPG难题

题目链接：http://acm.hdu.edu.cn/showproblem.php?pid=2045

#include <math.h>#include <stdio.h>int main(void){    int i;    __int64 d[51] = {0, 3, 6, 6};    for (i = 4; i < 51; i++)        d[i] = d[i-1] + 2*d[i-2];    while (scanf("%d", &i) != EOF)        printf("%I64d\n", d[i]);    return 0;}