杭电ACM2045题
#include<stdio.h>
int main()
{
int n;
while(scanf("%d",&n)!=EOF)
{
__int64 a[51];
int i;
a[1]=3;
a[2]=6;
a[3]=6;
for(i=4;i<=50;i++)
{
a[i]=a[i-1]+a[i-2]*2;
}
printf("%I64d\n",a[n]);
}
return 0;
}
#include<stdio.h>
int main()
{
int n;
while(scanf("%d",&n)!=EOF)
{
__int64 a[51];
int i;
a[1]=3;
a[2]=6;
a[3]=6;
for(i=4;i<=50;i++)
{
a[i]=a[i-1]+a[i-2]*2;
}
printf("%I64d\n",a[n]);
}
return 0;
}